Organic compound, anthracene derivative, and light-emitting element, light-emitting device, and electronic device in which the anthracene derivative is used

ABSTRACT

An anthracene derivative represented by a general formula (1) and an organic compound represented by a general formula (8) are provided. Further, by use of the anthracene derivative represented by the general formula (1), a light-emitting element with high emission efficiency can be obtained. Furthermore, by use of the anthracene derivative represented by the general formula (1), a light-emitting element that emits blue light with high color purity can be obtained.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to organic compounds, anthracenederivatives, and light-emitting elements, light-emitting devices, andelectronic devices in which the anthracene derivatives are used.

2. Description of the Related Art

In a light-emitting element, a layer containing an organic compound isinterposed between a pair of electrodes. Such a light-emitting elementis characterized in that a thin and lightweight element can befabricated, light is emitted by supply of direct current, response isfaster compared to liquid crystals, and the like. Moreover,light-emitting devices in which such light-emitting elements arearranged in matrix form, that is, passive matrix light-emitting devicesand active matrix light-emitting devices are superior to conventionalliquid crystal displays in terms of wide viewing angle and highvisibility. From such reasons, light-emitting elements are desired to beapplied to next-generation flat panel displays. In some cases,light-emitting elements are referred to as electroluminescent elementsor EL elements.

Electrons are injected from a cathode into a layer containing an organiccompound interposed between a pair of electrodes, and at the same time,holes are injected from an anode into the layer containing an organiccompound, whereby a light-emitting element is driven. The electronsinjected from the cathode and the holes injected from the anode arerecombined with each other in the layer containing an organic compoundto form molecular excitons. The molecular excitons release energy inreturning to a ground state. When the energy is released as light havinga wavelength corresponding to that of visible light, light emission canbe seen. Excited states of organic compounds include a singlet state anda triplet state, and when either state is the excited state, light canbe emitted.

An emission wavelength of a light-emitting element is determined by theenergy gap between a ground state and an excited state formed by therecombination, that is, a band gap. Therefore, a structure of a moleculethat serves for emitting light is selected or modified as appropriate,whereby any emission color of light can be obtained. Further, full colorlight-emitting device can be manufactured when light-emitting elementsthat are capable of emitting light of red, blue, and green that arethree primary colors of light are used for the manufacture of thelight-emitting device.

In order to manufacture a full color light-emitting device withexcellent color reproducibility, red, blue, and green light-emittingelements that are highly reliable and excellent in color purity areneeded. As a result of recent developments of materials, highreliability and excellent color purity for red and green light-emittingelements have been achieved. However, enough efficiency and color purityfor a blue light-emitting element have not been achieved. For example,in Nonpatent Document 1 (J. Shi et al., Applied Physics Letters, Vol.80, No. 17, pp. 3201-3203, 2002), a blue light-emitting element withrelatively high reliability is reported. For the light-emitting element,however, enough emission efficiency and color is not achieved.

SUMMARY OF THE INVENTION

In view of the foregoing problems, objects of the present invention areto provide novel anthracene derivatives and organic compounds.

Another object of the present invention is to provide a light-emittingelement with high emission efficiency. Further, another object of thepresent invention is to provide a light-emitting element that emits bluelight with high color purity.

Other objects of the present invention are to provide a light-emittingdevice and an electronic device in which power consumption is reduced.

As a result of diligent study, the present inventors have found that theproblems can be solved with an anthracene derivative represented by ageneral formula (1) given below. Thus, one aspect of the presentinvention is an anthracene derivative represented by a general formula(1) given below.

In the above general formula (1), Ar¹ and Ar² may be the same ordifferent from each other and each represent a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; α and β may be thesame or different from each other and each represent a substituted orunsubstituted arylene group having 6 to 25 carbon atoms; R¹ representsan alkyl group having 1 to 4 carbon atoms or a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; R² represents oneof hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group; and R¹¹ to R¹⁸ may be the same or different fromeach other and each represent hydrogen or an alkyl group having 1 to 4carbon atoms.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (2) given below.

In the above general formula (2), Ar¹ represents a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; α and β may be thesame or different from each other and each represent a substituted orunsubstituted arylene group having 6 to 25 carbon atoms; R¹ representsan alkyl group having 1 to 4 carbon atoms or a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; R² represents oneof hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group; R³ to R⁷ may be the same or different from eachother and each represent one of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, and a haloalkyl group; and R¹¹ to R¹⁸ maybe the same or different from each other and each represent hydrogen oran alkyl group having 1 to 4 carbon atoms.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (3) given below.

In the above general formula (3), Ar¹ and Ar² may be the same ordifferent from each other and each represent a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; α represents asubstituted or unsubstituted arylene group having 6 to 25 carbon atoms;R¹ represents an alkyl group having 1 to 4 carbon atoms or a substitutedor unsubstituted aryl group having 6 to 25 carbon atoms; R² representsone of hydrogen, an alkyl group having 1 to 4 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 25 carbon atoms, ahalogen group, and a haloalkyl group; and R¹¹ to R¹⁸ may be the same ordifferent from each other and each represent hydrogen or an alkyl grouphaving 1 to 4 carbon atoms.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (4) given below.

In the above general formula (4), Ar¹ each represents a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; α represents asubstituted or unsubstituted arylene group having 6 to 25 carbon atoms;R¹ represents an alkyl group having 1 to 4 carbon atoms or a substitutedor unsubstituted aryl group having 6 to 25 carbon atoms; R² representsone of hydrogen, an alkyl group having 1 to 4 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 25 carbon atoms, ahalogen group, and a haloalkyl group; R³ to R⁷ may be the same ordifferent from each other and each represent one of hydrogen, an alkylgroup having 1 to 4 carbon atoms, a halogen group, and a haloalkylgroup; and R¹¹ to R¹⁸ may be the same or different from each other andeach represent hydrogen or an alkyl group having 1 to 4 carbon atoms.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (5) given below.

In the above general formula (5), Ar¹ represents a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; R¹ represents analkyl group having 1 to 4 carbon atoms or a substituted or unsubstitutedaryl group having 6 to 25 carbon atoms; R² represents one of hydrogen,an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group; R³ to R⁷ may be the same or different from eachother and each represent one of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, and a haloalkyl group; R¹¹ to R¹⁸ may bethe same or different from each other and each represent hydrogen or analkyl group having 1 to 4 carbon atoms; and R¹⁹ to R²² may be the sameor different from each other and each represent one of hydrogen, analkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to4 carbon atoms.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (6) given below.

In the above general formula (6), R¹ represents an alkyl group having 1to 4 carbon atoms or a substituted or unsubstituted aryl group having 6to 25 carbon atoms; R² represents one of hydrogen, an alkyl group having1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6to 25 carbon atoms, a halogen group, and a haloalkyl group; R³ to R⁷ maybe the same or different from each other and each represent one ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,and a haloalkyl group; R¹¹ to R¹⁸ may be the same or different from eachother and each represent hydrogen or an alkyl group having 1 to 4 carbonatoms; and R¹⁹ to R²⁷ may be the same or different from each other andeach represent one of hydrogen, an alkyl group having 1 to 4 carbonatoms, and an alkoxy group having 1 to 4 carbon atoms.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (7) given below.

One aspect of the present invention is a light-emitting element thatcontains any of the above anthracene derivatives, that is, alight-emitting element that contains any of the above anthracenederivatives between a pair of electrodes.

Further, since the above anthracene derivatives have high emissionefficiency, it is preferred that each of them be used for alight-emitting layer. Thus, one aspect of the present invention is alight-emitting element that includes a light-emitting layer between apair of electrodes, where the light-emitting layer contains any of theabove anthracene derivatives.

The light-emitting element of the present invention thus obtained can bemade to have a long life, and thus, a light-emitting device (e.g., animage display device) in which such a light-emitting element is used canbe made to have a long life. Thus, the present invention also covers thelight-emitting device and an electronic device in which thelight-emitting element of the present invention is used.

The light-emitting device of the present invention is characterized inthat it includes a light-emitting element that contains any of theabove-described anthracene derivatives and a control circuit configuredto control light emission from the light-emitting element. The categoryof the light-emitting device in this specification includes an imagedisplay device in which a light-emitting element is used. Further, thecategory of the light-emitting device also includes a module in which aconnecter such as an anisotropic film, a tape automated bonding (TAB)tape, or a tape carrier package (TCP) is attached to a light-emittingelement; a module in which a printed wiring board is provided at an endof a TAB tape or a TCP; and a module in which an integrated circuit (IC)is directly mounted on a light-emitting element by a chip on glass (COG)method. In addition, the category includes a light-emitting device usedfor a lighting device or the like.

Further, an electronic device in which the light-emitting element of thepresent invention is used for its display portion is also included inthe category of the present invention. Accordingly, one aspect of thepresent invention is an electronic device having a display portion,where the display portion includes the above-described light-emittingelement and a control circuit configured to control light emission fromthe light-emitting element.

Furthermore, the present invention also covers organic compounds usedfor the synthesis of the anthracene derivatives of the present inventionbecause the organic compounds used for the synthesis of the anthracenederivatives of the present invention are novel materials. Accordingly,one aspect of the present invention is an organic compound representedby a general formula (8) given below.

In the above general formula (8), Ar² represents a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; β represents asubstituted or unsubstituted arylene group having 6 to 25 carbon atoms;R¹ represents an alkyl group having 1 to 4 carbon atoms or a substitutedor unsubstituted aryl group having 6 to 25 carbon atoms; and R²represents one of hydrogen, an alkyl group having 1 to 4 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 25 carbon atoms, ahalogen group, and a haloalkyl group.

One aspect of the present invention is an organic compound representedby a general formula (9) given below.

In the above general formula (9), β represents a substituted orunsubstituted arylene group having 6 to 25 carbon atoms; R¹ representsan alkyl group having 1 to 4 carbon atoms or a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; R² represents oneof hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group; and R³ to R⁷ may be the same or different fromeach other and each represent one of hydrogen, an alkyl group having 1to 4 carbon atoms, a halogen group, and a haloalkyl group.

One aspect of the present invention is an organic compound representedby a general formula (10) given below.

In the above general formula (10), Ar² represents a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; R¹ represents analkyl group having 1 to 4 carbon atoms or a substituted or unsubstitutedaryl group having 6 to 25 carbon atoms; and R² represents one ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group.

One aspect of the present invention is an organic compound representedby a general formula (11) given below.

In the above general formula (11), R¹ represents an alkyl group having 1to 4 carbon atoms or a substituted or unsubstituted aryl group having 6to 25 carbon atoms; R² represents one of hydrogen, an alkyl group having1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6to 25 carbon atoms, a halogen group, and a haloalkyl group; and R³ to R⁷may be the same or different from each other and each represent one ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,and a haloalkyl group.

One aspect of the present invention is an organic compound representedby a general formula (12) given below.

In the above general formula (12), R¹ represents an alkyl group having 1to 4 carbon atoms or a substituted or unsubstituted aryl group having 6to 25 carbon atoms; R² represents one of hydrogen, an alkyl group having1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6to 25 carbon atoms, a halogen group, and a haloalkyl group; and R³ to R⁷may be the same or different from each other and each represent one ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,and a haloalkyl group.

One aspect of the present invention is an organic compound representedby a general formula (13) given below.

The anthracene derivatives of the present invention have high emissionefficiency. Furthermore, the anthracene derivatives of the presentinvention can emit blue light with high color purity.

Furthermore, by use of any of the anthracene derivatives of the presentinvention, a light-emitting element with high emission efficiency can beobtained. Further, a light-emitting element that emits blue light withhigh color purity can also be obtained.

Furthermore, by use of any of the anthracene derivatives of the presentinvention, a light-emitting device and an electronic device in whichpower consumption is reduced can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a light-emitting element of the present invention.

FIG. 2 illustrates a light-emitting element of the present invention.

FIG. 3 illustrates a light-emitting element of the present invention.

FIGS. 4A and 4B illustrate a light-emitting device of the presentinvention.

FIGS. 5A and 5B illustrate a light-emitting device of the presentinvention.

FIGS. 6A to 6D illustrate electronic devices of the present invention.

FIG. 7 illustrates a lighting device of the present invention.

FIG. 8 illustrates a lighting device of the present invention.

FIG. 9 illustrates a lighting device of the present invention.

FIGS. 10A and 10B are ¹H-NMR charts of4-(9-phenyl-9H-carbazol-3-yl)diphenylamine (abbreviated to PCBA).

FIGS. 11A and 11B are ¹H-NMR charts of4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(abbreviated to PCBAPA).

FIG. 12 illustrates an absorption spectrum and an emission spectrum of atoluene solution of4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPA).

FIG. 13 illustrates an absorption spectrum and an emission spectrum of athin film of4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPA).

FIG. 14 illustrates a light-emitting element of Example 2.

FIG. 15 illustrates current density-luminance characteristics of alight-emitting element fabricated in Example 2.

FIG. 16 illustrates voltage-luminance characteristics of alight-emitting element fabricated in Example 2.

FIG. 17 illustrates luminance-current efficiency characteristics of alight-emitting element fabricated in Example 2.

FIG. 18 illustrates luminance-external quantum efficiencycharacteristics of a light-emitting element fabricated in Example 2.

FIG. 19 illustrates an emission spectrum of a light-emitting elementfabricated in Example 2.

FIG. 20 illustrates a light-emitting element of Example 3.

FIG. 21 illustrates current density-luminance characteristics of alight-emitting element fabricated in Example 3.

FIG. 22 illustrates voltage-luminance characteristics of alight-emitting element fabricated in Example 3.

FIG. 23 illustrates luminance-current efficiency characteristics of alight-emitting element fabricated in Example 3.

FIG. 24 illustrates luminance-external quantum efficiencycharacteristics of a light-emitting element fabricated in Example 3.

FIG. 25 illustrates an emission spectrum of a light-emitting elementfabricated in Example 3.

FIG. 26 illustrates a result of a continuous lighting test of alight-emitting element fabricated in Example 2.

FIG. 27 illustrates a result of a continuous lighting test of alight-emitting element fabricated in Example 3.

FIGS. 28A and 28B are ¹H-NMR charts of4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(abbreviated to PCBAPBA).

FIG. 29 illustrates an absorption spectrum of a toluene solution of4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPBA).

FIG. 30 illustrates an emission spectrum of a toluene solution of4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPBA).

FIG. 31 illustrates an absorption spectrum of a thin film of4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPBA).

FIG. 32 illustrates an emission spectrum of a thin film of4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPBA).

FIG. 33 illustrates current density-luminance characteristics of alight-emitting element fabricated in Example 5.

FIG. 34 illustrates voltage-luminance characteristics of alight-emitting element fabricated in Example 5.

FIG. 35 illustrates luminance-current efficiency characteristics of alight-emitting element fabricated in Example 5.

FIG. 36 illustrates an emission spectrum of a light-emitting elementfabricated in Example 5.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiment modes and examples of the present invention aredescribed using the accompanying drawings. It is easily understood bythose skilled in the art that a variety of changes may be made in formsand details without departing from the spirit and the scope of thepresent invention. Therefore, the present invention should not belimited to the description of the embodiment modes and examples below.

[Embodiment Mode 1]

In this embodiment mode, anthracene derivatives of the present inventionare described.

An anthracene derivative of the present invention is represented by thegeneral formula (1).

In the above general formula (1), Ar¹ and Ar² may be the same ordifferent from each other and each represent a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; α and β may be thesame or different from each other and each represent a substituted orunsubstituted arylene group having 6 to 25 carbon atoms; R¹ representsan alkyl group having 1 to 4 carbon atoms or a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; R² represents oneof hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group; and R¹¹ to R¹⁸ may be the same or different fromeach other and each represent hydrogen or an alkyl group having 1 to 4carbon atoms.

Structures shown in (Ar-1) to (Ar-19) are given as examples ofsubstituents represented by Ar¹ and Ar² in the above general formula(1). Further, Ar¹ may have an alkyl group having 1 to 4 carbon atoms oran alkoxy group having 1 to 4 carbon atoms. In fabrication of alight-emitting element by a wet process, using any of the anthracenederivatives of the present invention, it is preferred that Ar¹ have analkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4carbon atoms because such a structure increases the solubility of theanthracene derivative of the present invention.

Structures shown in (α-1) to (α-12) are given as examples of a structurerepresented by α in the above general formula (1). Further, α may havean alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to4 carbon atoms. When α has an alkyl group having 1 to 4 carbon atoms oran alkoxy group having 1 to 4 carbon atoms, the solubility of theanthracene derivative of the present invention is increased; therefore,a light-emitting element can be fabricated using any of the anthracenederivatives of the present invention by a wet process.

Structures shown in (β-1) to (β-10) are given as examples of a structurerepresented by β in the above general formula (1).

Structures shown in (R1-1) to (R1-21) are given as examples of asubstituent represented by R¹ in the above general formula (1).

Structures shown in (R2-1) to (R2-24) are given as examples of asubstituent represented by R² in the above general formula (1).

Specific examples of such an anthracene derivative of the presentinvention include, but are not limited to, anthracene derivativesrepresented by structural formulae (100) to (164) given below.

Any of a variety of reactions can be employed for a synthesis method ofthe anthracene derivatives of the present invention. For example, thesynthesis can be performed by use of any of the synthesis methods shownin synthesis schemes (a-1) to (a-3) given below.

First, 9-halid-10-arylanthracene (Compound 1) and halogenated arylboronic acid or halogenated aryl organic boron compound (Compound 7) arecoupled by Suzuki-Miyaura Coupling using a palladium catalyst, whereby9-(halogenated aryl)-10-arylanthracene (Compound 2) can be obtained. Inthe synthesis scheme, X¹ represents a halogen or a triflate group, andX² represents a halogen. When X¹ is a halogen, X¹ and X² may be the sameor different from each other. Use of iodine and bromine are preferablefor the halogen. It is more preferable that X¹ be iodine and that X² bebromine. Further, R¹⁰⁰ and R¹⁰¹ each represent hydrogen or an alkylgroup having 1 to 6 carbon atoms, may be the same or different from eachother, and may be combined with each other to form a ring. Ar¹represents a substituted or unsubstituted aryl group having 6 to 25carbon atoms. α represents a substituted or unsubstituted arylene grouphaving 6 to 25 carbon atoms. Examples of the palladium catalyst that canbe used in the synthesis scheme (a-1) include, but are not limited to,palladium(II) acetate, tetrakis(triphenylphosphine)palladium(0), and thelike. Examples of the ligand in the palladium catalyst, which can beused in the synthesis scheme (a-1), include, but are not limited to,tri(ortho-tolyl)phosphine, triphenylphosphine, tricyclohexylphosphine,and the like. Examples of the base that can be used in the synthesisscheme (a-1) include, but are not limited to, organic bases such assodium tert-butoxide, inorganic bases such as potassium carbonate, andthe like. Examples of the solvent that can be used in the synthesisscheme (a-1) include, but are not limited to, a mixed solvent of tolueneand water a mixed solvent of toluene, an alcohol such as ethanol, andwater, a mixed solvent of xylene and water, a mixed solvent of xylene,an alcohol such as ethanol, and water; a mixed solvent of benzene andwater; a mixed solvent of benzene, an alcohol such as ethanol, andwater, a mixed solvent of an ether such as ethyleneglycoldimethyletherand water; and the like. Use of the mixed solvent of toluene and wateror the mixed solvent of toluene, ethanol, and water is more preferable.

Diarylamine halide (Compound 3) and 9H-carbazole-3-boronic acid or acompound obtained by 9H-carbazole in which the 3-position is substitutedwith organoboron (Compound 4) are coupled by Suzuki-Miyaura Couplingusing a palladium catalyst, whereby a carbazole compound in which the3-position is substituted with diarylamine (Compound 5) can be obtained.In the synthesis scheme, Ar² represents a substituted or unsubstitutedaryl group having 6 to 25 carbon atoms X⁴ represents a halogen or atriflate group, and iodine or bromine can be used as the halogen. βrepresents a substituted or unsubstituted arylene group having 6 to 25carbon atoms. R¹ represents an alkyl group having 1 to 4 carbon atoms ora substituted or unsubstituted aryl group having 6 to 25 carbon atoms.R² represents one of hydrogen, an alkyl group having 1 to 4 carbonatoms, a substituted or unsubstituted aryl group having 6 to 25 carbonatoms, a halogen group, and a haloalkyl group. R¹⁰² and R¹⁰³ eachrepresent hydrogen or an alkyl group having 1 to 6 carbon atoms, may bethe same or different from each other, and combined with each other toform a ring. Examples of the palladium catalyst that can be used in thesynthesis scheme (a-2) include, but are not limited to, palladium(II)acetate, tetrakis(triphenylphosphine)palladium(0), and the like.Examples of the ligand that can be used in the synthesis scheme (a-2)include, but are not limited to, tri(ortho-tolyl)phosphine,triphenylphosphine, tricyclohexylphosphine, and the like. Examples ofthe base that can be used in the synthesis scheme (a-2) include, but arenot limited to, organic bases such as sodium tert-butoxide, inorganicbases such as potassium carbonate, and the like. Examples of the solventthat can be used in the synthesis scheme (a-2) include, but are notlimited to, a mixed solvent of toluene and water, a mixed solvent oftoluene, an alcohol such as ethanol, and water; a mixed solvent ofxylene and water; a mixed solvent of xylene, an alcohol such as ethanol,and water a mixed solvent of benzene and water; a mixed solvent ofbenzene, an alcohol such as ethanol, and water, a mixed solvent of anether such as ethyleneglycoldimethylether and water; and the like. Useof the mixed solvent of toluene and water or the mixed solvent oftoluene, ethanol, and water is more preferable.

Then, the 9-(halogenated aryl)-10-arylanthracene (Compound 2) obtainedby the synthesis scheme (a-1) and the carbazole compound in which the3-position is substituted with diarylamine (Compound 5) obtained by thesynthesis scheme (a-2) are coupled by a Buchwald-Hartwig reaction usinga palladium catalyst or an Ullmann reaction using copper or a coppercompound, whereby Compound 6 which is one of the anthracene derivativesof the present invention can be obtained. When a Buchwald-Hartwigreaction is performed in the synthesis scheme (a-3), examples of thepalladium catalyst that can be used in the synthesis scheme (a-3)include, but are not limited to, bis(dibenzylideneacetone)palladium(0),palladium(II) acetate, and the like. Examples of the ligand in thepalladium catalyst, which can be used in the synthesis scheme (a-3),include, but are not limited to, tri(tert-butyl)phosphine,tri(n-hexyl)phosphine, tricyclohexylphosphine, and the like. Examples ofthe base that can be used in the synthesis scheme (a-3) include, but arenot limited to, organic bases such as sodium tert-butoxide, inorganicbases such as potassium carbonate, and the like. Examples of the solventthat can be used in the synthesis scheme (a-3) include, but are notlimited to, toluene, xylene, benzene, tetrahydrofuran, and the like. Thecase in which an Ullmann reaction is performed in the synthesis scheme(a-3) is described. In the synthesis scheme (a-3), R¹⁰⁴ and R¹⁰⁵ eachrepresent a halogen, an acetyl group, or the like, and chlorine,bromine, or iodine can be used as the halogen. It is preferred that R¹⁰⁴be iodine to form copper(I) iodide or that R¹⁰⁵ be an acetyl group toform a copper(II) acetate. The copper compound used in the reaction isnot limited to these, and copper can be used instead of the coppercompound. Examples of the base that can be used in the synthesis scheme(a-3) include, but are not limited to, an inorganic base such aspotassium carbonate. Examples of the solvent that can be used in thesynthesis scheme (a-3) include, but are not limited to,1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)pyrimidinone (abbreviated to DMPU),toluene, xylene, benzene, and the like. Use of DMPU or xylene that has ahigh boiling point is preferable because, by an Ullmann reaction, anobject can be obtained in a shorter time and at a higher yield when thereaction temperature is greater than or equal to 100° C. Use of DMPU ismore preferable because it is further preferable that the reactiontemperature be a temperature greater than or equal to 150° C. In thesynthesis scheme, Ar¹ and Ar² may be the same or different from eachother and each represent a substituted or unsubstituted aryl grouphaving 6 to 25 carbon atoms. α and β may be the same or different fromeach other and each represent a substituted or unsubstituted arylenegroup having 6 to 25 carbon atoms. X² represents a halogen. R¹represents an alkyl group having 1 to 4 carbon atoms or a substituted orunsubstituted aryl group having 6 to 25 carbon atoms. R² represents oneof hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group.

The anthracene derivatives of the present invention have high emissionefficiency. Therefore, it is preferred that any of the anthracenederivatives of the present invention be used for a light-emittingelement. Furthermore, the anthracene derivatives of the presentinvention emit blue light with high color purity. Thus, it is preferredthat any of the anthracene derivatives of the present invention be usedfor a light-emitting device such as a full-color display that displaysimages. Further, the anthracene derivatives of the present invention canbe used as a hole-transporting layer of a light-emitting element sincethe anthracene derivatives of the present invention have ahole-transporting property.

[Embodiment Mode 2]

In this embodiment mode, organic compounds that are materials used forthe synthesis of the anthracene derivatives of the present invention aredescribed. These organic compounds are novel materials and thus includedin the present invention.

One of the organic compounds is the organic compound represented by thegeneral formula (8).

In the above general formula (8), Ar² represents a substituted orunsubstituted aryl group having 6 to 25 carbon atoms; β represents asubstituted or unsubstituted arylene group having 6 to 25 carbon atoms;R¹ represents an alkyl group having 1 to 4 carbon atoms or a substitutedor unsubstituted aryl group having 6 to 25 carbon atoms; and R²represents one of hydrogen, an alkyl group having 1 to 4 carbon atoms, asubstituted or unsubstituted aryl group having 6 to 25 carbon atoms, ahalogen group, and a haloalkyl group.

Structures shown in (Ar2-1) to (Ar2-19) are given as examples of asubstituent represented by Ar² in the above general formula (8).

Structures shown in (β-1) to (β-10) are given as examples of a structurerepresented by β in the above general formula (8).

Structures shown in (R1-1) to (R1-21) are given as examples of asubstituent represented by R¹ in the above general formula (8).

Structures shown in (R2-1) to (R2-24) are given as examples of asubstituent represented by R² in the above general formula (8).

Specific examples of the organic compounds of the present inventioninclude, but are not limited to, organic compounds represented bystructural formulae (200) to (264) given below.

Any of a variety of reactions can be employed for a synthesis method ofthe above organic compounds of the present invention. For example, thesynthesis can be performed by a synthesis method that is similar to thatof the compound 5 described in Embodiment Mode 1 (the synthesis scheme(a-2)).

[Embodiment Mode 3]

In this embodiment mode, one mode of a light-emitting element in whichany of the anthracene derivatives of the present invention is used isdescribed below using FIG. 1.

The light-emitting element of the present invention includes a pluralityof layers between a pair of electrodes. For the plurality of layers,layers that each contain a substance having a high carrier-injectingproperty or a substance having a high carrier-transporting property arecombined and stacked so that a light-emitting region is formed apartfrom the electrodes, in other words, carriers are recombined in aportion apart from the electrodes.

In this embodiment mode, the light-emitting element includes a firstelectrode 101, a second electrode 103, and a layer 102 that contains anorganic compound formed between the first electrode 101 and the secondelectrode 103. It is to be noted that, in this embodiment mode, it isassumed that the first electrode 101 serves as an anode and the secondelectrode 103 serves as a cathode. In other words, in the descriptionbelow, it is assumed that light emission can be obtained when a voltageis applied to the first electrode 101 and the second electrode 103 sothat the potential of the first electrode 101 is higher than that of thesecond electrode 103.

A substrate 100 is used as a support of the light-emitting element. Forthe substrate 100, glass, plastic, or the like can be used. It is to benoted that any material other than these can be used as long as it canfunction as a support in a fabrication process of a light-emittingelement.

It is preferred that the first electrode 101 be formed using any ofmetals, alloys, and conductive compounds with a high work function(specifically, 4.0 eV or higher), a mixture thereof, or the like.Specifically, indium tin oxide (ITO), indium tin oxide containingsilicon or silicon oxide, indium zinc oxide (IZO), indium oxidecontaining tungsten oxide and zinc oxide (IWZO), or the like can beused. Such conductive metal oxide films are typically formed bysputtering, but may also be formed by application of a sol-gel method orthe like. For example, a film of indium zinc oxide (IZO) can be formedusing a target in which 1 wt % to 20 wt % of zinc oxide is added toindium oxide by a sputtering method. A film of indium oxide containingtungsten oxide and zinc oxide (IWZO) can be formed using a target inwhich 0.5 wt % to 5 wt % of tungsten oxide and 0.1 wt % to 1 wt % ofzinc oxide are added to indium oxide by a sputtering method.Furthermore, gold (Au), platinum (Pt), nickel (Ni), tungsten (W),chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu),palladium (Pd), nitride of a metal material (e.g., titanium nitride), orthe like can be used.

When a layer containing a composite material that is described later isused as a layer in contact with the first electrode 101, the firstelectrode 101 can be formed using any of a variety of metals, alloys,electrically conductive compounds, a mixture thereof, or the likeregardless of their work functions. For example, aluminum (Al), silver(Ag), an alloy containing aluminum (AlSi), or the like can be used.Alternatively, any of the following materials with a low work functioncan be used: Group 1 and Group 2 elements of the periodic table, thatis, alkali metals such as lithium (Li) and cesium (Cs) andalkaline-earth metals such as magnesium (Mg), calcium (Ca), or strontium(Sr), or alloys thereof (e.g., MgAg and AlLi); rare earth metals such aseuropium (Eu) or ytterbium (Yb), and alloys thereof; or the like. A filmcontaining an alkali metal, an alkaline earth metal, or an alloy thereofcan be formed by a vacuum evaporation method. Alternatively, a filmcontaining an alloy of an alkali metal or an alkaline earth metal can beformed by a sputtering method. Further alternatively, such a film can beformed using a silver paste or the like by an inkjet method or the like.

There is no particular limitation on a stacked structure of a layer 102containing an organic compound. It is acceptable as long as the layer102 containing an organic compound is formed by any appropriatecombination of a light-emitting layer described in this embodiment modeand layers that each contain a substance having a highelectron-transporting property, a substance having a highhole-transporting property, a substance having a high electron-injectingproperty, a substance having a high hole-injecting property, a bipolarsubstance (a substance having a high electron-transporting property anda high hole-transporting property), or the like. For example, ahole-injecting layer, a hole-transporting layer, a light-emitting layer,an electron-transporting layer, an electron-injecting layer, and thelike can be combined. In this embodiment mode, the layer 102 containingan organic compound has a structure in which a hole-injecting layer 111,a hole-transporting layer 112, a light-emitting layer 113, and anelectron-transporting layer 114 are sequentially stacked over the firstelectrode 101. A material of each layer is described in specific termsbelow.

The hole-injecting layer 111 is a layer that contains a substance havinga high hole-injecting property. Molybdenum oxide, vanadium oxide,ruthenium oxide, tungsten oxide, manganese oxide, or the like can beused. Alternatively, the hole-injecting layer 111 can also be formedusing any of phthalocyanine based compounds such as phthalocyanine(abbreviated to H₂PC) or copper phthalocyanine (abbreviated to CuPc),aromatic amine compounds such as4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviatedto DPAB) or4,4′-bis(N-{4-[N-(3-methylphenyl)-N-phenylamino]phenyl}-N-phenylamino)biphenyl(abbreviated to DNTPD), compounds with a high molecular weight such aspoly(3,4-ethylenedioxythiophene)/poly(styrenesulfonic acid) (abbreviatedto PEDOT/PSS), or the like.

Alternatively, for the hole-injecting layer 111, a composite material inwhich an acceptor substance is mixed into a substance having a highhole-transporting property can be used. It is to be noted that amaterial of the electrode can be selected regardless of its workfunction by use of the composite material in which an acceptor substanceis mixed into a substance having a high hole-transporting property. Thatis, not only a material with a high work function, but also a materialwith a low work function can be used for the first electrode 101.Examples of the acceptor substance include7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated toF₄-TCNQ), chloranil, transition metal oxide, oxide of metals that belongto Group 4 to Group 8 of the periodic table, and the like. Specifically,vanadium oxide, niobium oxide, tantalum oxide, chromium oxide,molybdenum oxide, tungsten oxide, manganese oxide, or rhenium oxide ispreferably used because of their high electron accepting properties. Inparticular, use of molybdenum oxide is more preferable because of itsstability in the atmosphere, a low hygroscopic property, and easilyhandling.

As the substance having a high hole-transporting property used for thecomposite material, any of a variety of compounds such as aromatic aminecompounds, carbazole derivatives, aromatic hydrocarbons, compounds witha high molecular weight (such as oligomers, dendrimers, or polymers), orthe like can be used. It is to be noted that a substance having a holemobility of greater than or equal to 10⁻⁶ cm²/(V·s) is preferably usedas the substance having a high hole-transporting property. However, anysubstance other than the above substances may also be used as long as itis a substance in which the hole-transporting property is higher thanthe electron-transporting property. The organic compounds each of whichcan be used for the composite material are described in specific termsbelow.

Examples of the aromatic amine compounds each of which can be used forthe composite material includeN,N′-bis(4-methylphenyl)(p-tolyl)-N,N′-diphenyl-p-phenylenediamine(abbreviated to DTDPPA),4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB),4,4′-bis(N-{4-[N′-(3-methylphenyl)-N′-phenylamino]phenyl}-N-phenylamino)biphenyl(DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene(abbreviated to DPA3B), and the like.

Specific examples of the carbazole derivatives each of which can be usedfor the composite material include3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole(abbreviated to PCzPCA1);3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole(abbreviated to PCzPCA2),3-[N-(1-naphtyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole(abbreviated to PCzPCN1), and the like.

Moreover, examples of the carbazole derivatives that can be used for thecomposite material also include 4,4′-di(N-carbazolyl)biphenyl(abbreviated to CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene(abbreviated to TCPB), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(abbreviated to CzPA),1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, and thelike.

Examples of the aromatic hydrocarbons each of which can be used for thecomposite material include 2-tert-butyl-9,10-di(2-naphthyl)anthracene(abbreviated to t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene,9,10-bis(3,5-diphenylphenyl)anthracene (abbreviated to DPPA),2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviated tot-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviated to DNA),9,10-diphenylanthracene (abbreviated to DPAnth), 2-tert-butylanthracene(abbreviated to t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene(abbreviated to DMNA),9,10-bis[2-(1-naphthyl)phenyl]-2-tert-butylanthracene,9,10-bis[2-(1-naphthyl)phenyl]anthracene,2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene,2,3,6,7-tetramethyl-9, 10-di(2-naphthyl)anthracene, 9,9′-bianthryl, 10,0′-diphenyl-9,9′-bianthryl, 10,10′-bis(2-phenylphenyl)-9,9′-bianthryl,10,10′-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9′-bianthryl, anthracene,tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, andthe like. Besides these compounds, pentacene, coronene, or the like canalso be used. In particular, use of an aromatic hydrocarbon that has ahole mobility of greater than or equal to 1×10⁻⁶ cm²/(V·s) and has 14 to42 carbon atoms is more preferable.

It is to be noted that the aromatic hydrocarbons each of which can beused for the composite material may have a vinyl skeleton. Examples ofthe aromatic hydrocarbons having a vinyl skeleton include4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviated to DPVBi),9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated to DPVPA),and the like.

For the hole-injecting layer 111, any of compounds with a high molecularweight (such as oligomers, dendrimers, or polymers) can be used. Forexample, any of compounds with a high molecular weight such aspoly(N-vinylcarbazole) (abbreviated to PVK), poly(4-vinyltriphenylamine)(abbreviated to PVTPA),poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide](abbreviated to PTPDMA), andpoly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine] (abbreviated toPoly-TPD) can be given. Further, compounds with a high molecular weight,which is mixed with acid, such aspoly(3,4-ethylenedioxythiophene)/poly(styrenesulfonic acid) (PEDOT/PSS)or polyaniline/poly(styrenesulfonic acid) (abbreviated to PAni/PSS) canbe used.

Alternatively, for forming the hole-injecting layer 111, theabove-described compounds with a high molecular weight, such as PVK,PVTPA, PTPDMA, or Poly-TPD, may be combined with the above-describedacceptor substance to form a composite material.

The hole-transporting layer 112 is a layer that contains a substancehaving a high hole-transporting property. Examples of the substancehaving a high hole-transporting property include aromatic aminecompounds such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(abbreviated to NPB),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(abbreviated to TPD), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine(abbreviated to TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine(abbreviated to m-MTDATA), and4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]-1,1′-biphenyl(abbreviated to BSPB), and the like. These substances described heremainly are substances each having a hole mobility of greater than orequal to 10⁻⁶ cm²/(V·s). However, any substance other than the abovesubstances may also be used as long as it is a substance in which thehole-transporting property is higher than the electron-transportingproperty. It is to be noted that the layer that contains a substancehaving a high hole-transporting property is not limited to a singlelayer and may be a stack of two or more layers each containing theaforementioned substance.

For the hole-transporting layer 112, compounds with a high molecularweight such as PVK, PVTPA, PTPDMA, or Poly-TPD can also be used.

The light-emitting layer 113 is a layer that contains a substance havinga high light-emitting property. In the light-emitting element of thisembodiment mode, the light-emitting layer 113 contains any of theanthracene derivatives of the present invention that are described inEmbodiment Mode 1. The anthracene derivatives of the present inventionare suitable for use in a light-emitting element as a substance having ahigh light-emitting property because the anthracene derivatives of thepresent invention exhibit high emission efficiency.

The electron-transporting layer 114 is a layer that contains a substancehaving a high electron-transporting property. For example, metalcomplexes having a quinoline or benzoquinoline skeleton, such astris(8-quinolinolato)aluminum (abbreviated to Alq),tris(4-methyl-8-quinolinolato)aluminum (abbreviated to Almq₃),bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviated to BeBq₂), orbis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (abbreviated toBAlq) or the like can be used. Alternatively, metal complexes having anoxazole-based or thiazole-based ligand, such asbis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviated to Zn(BOX)₂) orbis[2-(2-hydroxyphenyl)-benzothiazolato]zinc (abbreviated to Zn(BTZ)₂)or the like can be used. In stead of the metal complexes,2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated toPBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene(abbreviated to OXD-7),3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole(abbreviated to TAZ), bathophenanthroline (abbreviated to BPhen),bathocuproine (abbreviated to BCP), or the like can also be used. Thesubstances described here mainly are substances each having an electronmobility of greater than or equal to 10⁻⁶ cm²/(V·s). It is to be notedthat any substance other than the above substances may also be used aslong it is a substance in which the electron-transporting property ishigher than the hole-transporting property. Furthermore, theelectron-transporting layer is not limited to a single layer and may bea stack of two or more layers each containing the aforementionedsubstance.

For the electron-transporting layer 114, any of compounds with a highmolecular weight can be used. For example,poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridin-3,5-diyl)] (abbreviatedto PF-Py),poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridin-6,6′-diyl)](abbreviated to PF-BPy), or the like can be used.

An electron-injecting layer may be provided between theelectron-transporting layer 114 and the second electrode 103. Theelectron-injecting layer can be formed using an alkali metal compound oran alkaline earth metal compound such as lithium fluoride (LiF), cesiumfluoride (CsF), or calcium fluoride (CaF₂). Furthermore, a layer inwhich a substance having an electron-transporting property is combinedwith an alkali metal or an alkaline earth metal can be employed. Forexample, it is possible to use a layer made of Alq containing magnesium(Mg). It is more preferable to use the layer in which a substance havingan electron-transporting property is combined with an alkali metal or analkaline earth metal as the electron-injecting layer because electroninjection from the second electrode 103 efficiently proceeds by the useof such a layer.

The second electrode 103 can be formed using a metal, an alloy, or aconductive compound with a low work function (specifically, 3.8 eV orlower), a mixture of them, or the like. Specific examples of suchcathode materials include elements belonging to Group 1 and Group 2 ofthe periodic table, that is, alkali metals such as lithium (Li) andcesium (Cs) and alkaline earth metals such as magnesium (Mg), calcium(Ca), and strontium (Sr); alloys of them (e.g., MgAg and AlLi); rareearth metals such as europium (Eu) and ytterbium (Yb), alloys of them;and the like. A film containing an alkali metal, an alkaline earthmetal, or an alloy thereof can be formed by a vacuum evaporation method.Alternatively, a film containing an alkali metal, an alkaline earthmetal, or an alloy thereof can be formed by a sputtering method. Furtheralternatively, such a film can be formed using a silver paste or thelike by an inkjet method or the like.

Further, when the electron-injecting layer is provided between thesecond electrode 103 and the electron-transporting layer 114, any of avariety of conductive materials such as Al, Ag, ITO, and ITO containingsilicon or silicon oxide can be used for the second electrode 103regardless of its work function. Films of these conductive materials canbe formed by a sputtering method, an inkjet method, a spin coatingmethod, or the like.

In the light-emitting element having the above structure which isdescribed in this embodiment mode, application of a voltage between thefirst electrode 101 and the second electrode 103 makes current flow,whereby holes and electrons are recombined in the light-emitting layer113 which is a layer that contains a substance having a highlight-emitting property, and light is emitted. That is, a light-emittingregion is formed in the light-emitting layer 113.

Light is extracted outside through one or both of the first electrode101 and the second electrode 103. Thus, one or both of the firstelectrode 101 and the second electrode 103 are light-transmissiveelectrodes. When only the first electrode 101 is a light-transmissiveelectrode, light is extracted from the substrate side through the firstelectrode 101. In contrast, when only the second electrode 103 is alight-transmissive electrode, light is extracted from a side opposite tothe substrate side through the second electrode 103. When both the firstelectrode 101 and the second electrode 103 are light-transmissiveelectrodes, light is extracted from both the substrate side and the sideopposite to the substrate side through the first electrode 101 and thesecond electrode 103.

Although FIG. 1 shows a structure in which the first electrode 101 thatfunctions as an anode is provided on the substrate 100 side, the secondelectrode 103 that functions as a cathode may be provided on thesubstrate 100 side.

Any of a variety of methods can be employed for forming the layer 102that contains an organic compound regardless of whether the method is adry process or a wet process. Further, different deposition methods maybe employed for each electrode or layer. A vacuum evaporation method, asputtering method, or the like can be employed as a dry process. Aninkjet method, a spin-coating method, or the like can be employed as awet process.

Similarly, the electrodes may be formed by a wet process such as asol-gel process or formed using a metal paste by a wet process.Alternatively, the electrodes may be formed by a dry process such as asputtering method or a vacuum evaporation method.

Hereinafter, a specific fabrication method of a light-emitting elementis described. When a light-emitting element of the present invention isapplied to a display device and light-emitting layers are formedseparately for each color, it is preferable to form the light-emittinglayer by a wet process. The use of a wet process such as an inkjetmethod makes it easier to form light-emitting layers separately for eachcolor even if a large substrate is employed, whereby productivity isimproved.

For example, in the structure described in this embodiment mode, thefirst electrode may be formed by a sputtering method which is a dryprocess; the hole-injecting layer may be formed by an inkjet method or aspin coating method which is a wet process; the hole-transporting layermay be formed by a vacuum evaporation method which is a dry process; thelight-emitting layer may be formed by an inkjet method which is a wetprocess; the electron-injecting layer may be formed by a co-depositionmethod which is a dry process; and the second electrode may be formed byan inkjet method or a spin coating method which is a wet process.Alternatively, the first electrode may be formed by an inkjet methodwhich is a wet process; the hole-injecting layer may be formed by avacuum evaporation method which is a dry process; the hole-transportinglayer may be formed by an inkjet method or a spin coating method whichis a wet process; the light-emitting layer may be formed by an inkjetmethod which is a wet process; the electron-injecting layer may beformed by an inkjet method or a spin coating method which is a wetprocess; and the second electrode may be formed by an inkjet method or aspin coating method which is a wet process. It is to be noted that thereis no limitation on the above methods and a wet process and that a dryprocess can be combined as appropriate.

Further alternatively, for example, the first electrode can be formed bya sputtering method which is a dry process; the hole-injecting layer andthe hole-transporting layer can be formed by an inkjet method or a spincoating method which is a wet process; the light-emitting layer can beformed by an inkjet method which is a wet process; theelectron-injecting layer can be formed by a vacuum evaporation methodwhich is a dry process; and the second electrode can be formed by avacuum evaporation method which is a dry process. In other words, on asubstrate on which the first electrode having a desired shape is formed,a wet process can be employed in the formation of the hole-injectinglayer to the light-emitting layer, and a dry process can be employed inthe formation of the electron-injecting layer to the second electrode.In this method, the formation of the hole-injecting layer to thelight-emitting layer can be performed at atmospheric pressure, and thelight-emitting layers can be easily formed separately for each color. Inaddition, the formation of the electron-injecting layer to the secondelectrode can be performed in vacuum consistently. Thus, the process canbe simplified, and productivity can be improved.

In the light-emitting element of the present invention having thestructure as described above, the potential difference generated betweenthe first electrode 101 and the second electrode 103 makes current flow,whereby holes and electrons are recombined in the light-emitting layer113 that is a layer containing a high light-emitting property, and thuslight is emitted. That is, a light-emitting region is formed in thelight-emitting layer 113.

It is to be noted that the structure of the layers provided between thefirst electrode 101 and the second electrode 103 is not limited to theabove one and may employ any structure as long as the light-emittingregion for the recombination of holes and electrons is positioned awayfrom the first electrode 101 and the second electrode 103 so as toprevent quenching caused by the light-emitting region being close to ametal.

The anthracene derivatives have high emission efficiency; therefore, asdescribed in this embodiment mode, any of the anthracene derivatives ofthe present invention can be used for a light-emitting layer without anyneed for any other light-emitting substance. Furthermore, since theanthracene derivatives of the present invention have high emissionefficiency, a light-emitting element with high emission efficiency canbe obtained.

The anthracene derivatives of the present invention emit blue light withhigh color purity, and thus a light-emitting element that emits bluelight with high color purity can be obtained.

Furthermore, the anthracene derivatives of the present invention emitblue light with high color purity at high efficiency, and thus alight-emitting element that can emit blue light with high luminousefficiency can be obtained.

Furthermore, by use of any of the anthracene derivatives of the presentinvention, a light-emitting element with a long life can be obtained.

Further, since the light-emitting element in which any of the anthracenederivatives of the present invention is used can emit blue light at highefficiency, the light-emitting element is suitable for use in afull-color display. Furthermore, the light-emitting element can emitblue light for a long period of time; therefore, the light-emittingelement is suitable for use in a full-color display. In particular, thedevelopment of blue light-emitting elements lags behind that of red orgreen light-emitting elements in terms of life and efficiency, and bluelight-emitting elements having good characteristics are desired. Sincethe light-emitting element in which any of the anthracene derivatives ofthe present invention is used can emit blue light at high efficiency fora long period of time, the light-emitting element is suitable for use ina full-color display.

[Embodiment Mode 4]

In this embodiment mode, a light-emitting element having a structurethat is different from that described in Embodiment Mode 3 is described.

In the light-emitting layer 113 described in Embodiment Mode 3, any ofthe anthracene derivatives of the present invention is dispersed intoanother substance, whereby light emission from the anthracene derivativeof the present invention can be obtained. Since the anthracenederivatives of the present invention emit blue light, a light-emittingelement that emits blue light can be obtained.

In this embodiment mode, any of a variety of materials can be used asthe substance in which one of the anthracene derivatives of the presentinvention is dispersed. In addition to the substance having a highhole-transporting property and the substance having a highelectron-transporting property, which are described in Embodiment Mode2, 4,4′-di(N-carbazolyl)-biphenyl (CBP),2,2′,2″-(1,3,5-benzenetriyl)-tris[1-phenyl-1H-benzimidazole](abbreviated to TPBI), 9,10-di(2-naphthyl)anthracene (DNA),2-tert-butyl-9,10-di(2-naphthyl)anthracene (t-BuDNA),9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (CzPA), or the like canbe used. Further, as the substance in which one of the anthracenederivatives of the present invention is dispersed, any of compounds witha high molecular weight can be used. For example, poly(N-vinylcarbazole)(PVK), poly(4-vinyltriphenylamine) (PVTPA),poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide](PTPDMA),poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine](Poly-TPD),poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (PF-Py),poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)](PF-BPy), or the like can be used.

Since the anthracene derivatives of the present invention have highemission efficiency, by use of any of the anthracene derivatives of thepresent invention in a light-emitting element, a light-emitting elementwith high emission efficiency can be obtained.

Since the anthracene derivatives of the present invention emit bluelight with high color purity, a light-emitting element that emits bluelight with high color purity can be obtained.

Furthermore, since the anthracene derivatives of the present inventionemit light at high efficiency, a light-emitting element that can emitblue light with high luminous efficiency can be obtained.

Furthermore, by use of any of the anthracene derivatives of the presentinvention, a light-emitting element with a long life can be obtained.

Since the light-emitting element in which any of the anthracenederivatives of the present invention is used can emit blue light withhigh color purity at high efficiency, the light-emitting element issuitable for use in a full-color display. Further, since thelight-emitting element can emit blue light for a long period of time,the light-emitting element is suitable for use in a full-color display.

It is to be noted that, except for the light-emitting layer 113, thestructure described in Embodiment Mode 3 can be used as appropriate.

[Embodiment Mode 5]

In this embodiment mode, a light-emitting element having a structurethat is different from the structures described in Embodiment Modes 3and 4 is described.

In the light-emitting layer 113 described in Embodiment Mode 3, alight-emitting substance is dispersed into any of the anthracenederivatives of the present invention, whereby light emission from thelight-emitting substance can be obtained.

When any of the anthracene derivatives of the present invention is usedas a material in which another light-emitting substance is dispersed, acolor generated by the light-emitting substance can be obtained.Further, a mixture of colors generated by the anthracene derivative ofthe present invention and the light-emitting substance dispersed in theanthracene derivative can also be obtained.

In this case, any of a variety of materials can be used as thelight-emitting substance dispersed in the anthracene derivative of thepresent invention. Specifically, it is possible to use any offluorescent substances that emit fluorescence, such asN,N′-diphenylquinacridon (abbreviated to DPQd), coumarin 6, coumarin545T, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran(abbreviated to DCM1),4-(dicyanomethylene)-2-methyl-6-(julolidin-4-yl-vinyl)-4H-pyran(abbreviated to DCM2), N,N-dimethylquinacridone (abbreviated to DMQd),{2-(1,1-dimethylethyl)-6-[2-(2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile(abbreviated to DCJTB), 5,12-diphenyltetracene (abbreviated to DPT),4-(9H-carbazol-9-yl)-4′-(10-phenyl-9-anthryl)triphenylamine (abbreviatedto YGAPA),4,4′-(2-tert-butylanthracen-9,10-diyl)bis{N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylaniline}(abbreviated to YGABPA),N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine(abbreviated to PCAPA),N,N′-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N′,N-triphenyl-1,4-phenylenediamine](abbreviated to DPABPA),N,N-bis[4-(9H-carbazol-9-yl)phenyl]-N,N-diphenylstilbene-4,4′-diamine(abbreviated to YGA2S),N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylstilben-4-amine (abbreviated toYGAS), N,N-diphenyl-N, N-bis(9-phenylcarbazol-3-yl)stilbene-4,4′-diamine(abbreviated to PCA2S), 4,4′-bis(2,2-diphenylvinyl)biphenyl (DPVBi),2,5,8,11-tetra(tert-butyl)perylene (abbreviated to TBP), perylene,rubrene, and 1,3,6,8-tetraphenylpyrene. Moreover, any of phosphorescentsubstances that emit phosphorescence such as(acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III)(abbreviated to Ir(Fdpq)2(acac)), and(2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinato)platinum(II)(abbreviated to PtOEP) can be used.

It is to be noted that, except for the light-emitting layer 113, thestructure described in Embodiment Mode 3 can be employed as appropriate.

[Embodiment Mode 6]

In this embodiment mode, a light-emitting element having a structurethat is different from the structures described in Embodiment Modes 3 to5 is described using FIG. 2.

In the light-emitting element described in this embodiment mode, a firstlayer 121 and a second layer 122 are provided in the light-emittinglayer 113 of the light-emitting element described in Embodiment Mode 3.

The light-emitting layer 113 is a layer that contains a substance havinga high light-emitting property. In the light-emitting element of thepresent invention, the light-emitting layer 113 has the first layer 121and the second layer 122. The first layer 121 contains a first organiccompound and an organic compound having a hole-transporting property,and the second layer 122 contains a second organic compound and anelectron-transporting organic compound. The first layer 121 is providedon the first electrode side of the second layer 122, in other words, incontact with an anode side of the second layer 122.

Each of the first organic compound and the second organic compound is asubstance having a high light-emitting property. In the light-emittingelement described in this embodiment mode, the first organic compound orthe second organic compound contains any of the anthracene derivativesof the present invention which are described in Embodiment Mode 1. Sincethe anthracene derivatives of the present invention emit blue light withhigh color purity, the anthracene derivatives are each suitable for useas a substance having a high light-emitting property in thelight-emitting element described in this embodiment mode. The firstorganic compound and the second organic compound may be the same ordifferent from each other.

When any of the anthracene derivatives of the present invention is usedas one of the first organic compound and the second organic compound, asthe other one thereof, it is possible to use substances that emit bluishlight, such as4-(9H-carbazol-9-yl)-4′-(10-phenyl-9-anthryl)triphenylamine (YGAPA),4,4′-(2-tert-butylanthracen-9,10-diyl)bis{N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylaniline}(YGABPA),N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine(PCAPA),N,N″-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N′N′-triphenyl-1,4-phenylenediamine](DPABPA),N,N′-bis[4-(9H-carbazol-9-yl)phenyl]-N,N′-diphenylstilbene-4,4′-diamine(YGA2S), N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylstilbene-4-amine (YGAS),N,N′-diphenyl-N, N-bis(9-phenylcarbazol-3-yl)stilbene-4,4′-diamine(PCA2S), 4,4′-bis(2,2-diphenylvinyl)biphenyl (DPVBi),2,5,8,11-tetra(tert-butyl)perylene (TBP), perylene, rubrene, and1,3,6,8-tetraphenylpyrene. Since each of these substances exhibits lightof a color that is similar to that of each anthracene derivatives of thepresent invention, they are suitable for use in the light-emittingelement of this embodiment mode.

The organic compound having a hole-transporting property, which iscontained in the first layer 121, is a substance in which thehole-transporting property is higher than the electron-transportingproperty. The organic compound having an electron-transporting property,which is contained in the second layer 122, is a substance in which theelectron-transporting property is higher than the hole-transportingproperty.

The light-emitting element of the present invention having theabove-described structure is described using FIG. 2 in accordance withthe principle below.

In FIG. 2, holes injected from the first electrode 101 are injected intothe first layer 121. The holes injected into the first layer 121 aretransported through the first layer 121 and further injected into thesecond layer 122. At this time, since the organic compound having anelectron-transporting property, which is contained in the second layer122, is a substance in which the electron-transporting property ishigher than the hole-transporting property, the holes injected into thesecond layer 122 have difficulty moving. Consequently, a large number ofholes come to be present near the interface between the first layer 121and the second layer 122. In addition, occurrence of a phenomenon inwhich holes reach the electron-transporting layer 114 withoutrecombining with electrons can be suppressed.

On the other hand, electrons injected from the second electrode 103 areinjected into the second layer 122. The electrons injected into thesecond layer 122 are transported through the second layer 122 andfurther injected into the first layer 121. At this time, since theorganic compound having a hole-transporting property, which is containedin the first layer 121, is a substance in which the hole-transportingproperty is higher than the electron-transporting property, theelectrons injected into the first layer 121 have difficulty moving.Consequently, a large number of electrons come to be present near theinterface between the first layer 121 and the second layer 122. Inaddition, occurrence of a phenomenon in which electrons reach thehole-transporting layer 112 without recombining with holes can besuppressed.

As described above, a large number of holes and electrons come to bepresent in a region in the vicinity of the interface between the firstlayer 121 and the second layer 122, and thus, the probability ofrecombination in the region in the vicinity of the interface can beincreased. That is, the light-emitting region is formed in the vicinityof the center of the light-emitting layer 113. As a result, occurrenceof a phenomenon in which holes reach the electron-transporting layer 114without recombining with electrons or electrons reach thehole-transporting layer 112 without recombining with holes can besuppressed, whereby a reduction in the probability of recombination canbe prevented. Since a reduction of carrier balance over time can thus beprevented, an improvement in reliability is promoted.

In order that holes and electrons be injected into the first layer 121,it is preferred that the organic compound having a hole-transportingproperty be an organic compound which can be oxidized and reduced andhas a highest occupied molecular orbital level (HOMO level) of greaterthan or equal to −6.0 eV and less than or equal to −5.0 eV as well as alowest unoccupied molecular orbital level (LUMO level) of greater thanor equal to −3.0 eV and less than or equal to −2.0 eV.

As such an organic compound that can be oxidized and reduced, use ofanthracene derivatives is particularly preferable among tricyclicpolyacene derivatives, tetracyclic polyacene derivatives, pentacyclicpolyacene derivatives, and hexacyclic polyacene derivatives. Specificexamples of the organic compound having an hole-transporting property,which is contained in the first layer 121, include9,10-diphenylanthracene (DPAnth),N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine(abbreviated to CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine(abbreviated to DPhPA),N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine(PCAPA),N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazol-3-amine(abbreviated to PCAPBA), and the like.

Similarly, in order that holes and electrons be injected into the secondlayer 122, it is preferred that the organic compound having anelectron-transporting property be an organic compound which can beoxidized and reduced and has a HOMO level of greater than or equal to−6.0 eV and less than or equal to −5.0 eV.

As such an organic compound which can be oxidized and reduced, any oftricyclic polyacene derivatives, tetracyclic polyacene derivatives,pentacyclic polyacene derivatives, or hexacyclic polyacene derivativescan be given. Specifically, any of anthracene derivatives, phenanthrenederivatives, pyrene derivatives, chrysene derivatives,dibenzo[g,p]chrysene derivatives, or the like can be given. For example,as a compound having an electron-transporting property, which can beused for the second layer,9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (CzPA),3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviatedto DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene (DPPA),9,10-di(2-naphthyl)anthracene (DNA),2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviated to t-BuDNA),9,9′-bianthryl (abbreviated to BANT),9,9′-(stilbene-3,3′-diyl)diphenanthrene (abbreviated to DPNS),9,9′-(stilbene-4,4′-diyl)diphenanthrene (abbreviated to DPNS2),3,3′,3″-(benzene-1,3,5-triyl)tripyrene (abbreviated to TPB3), and thelike can be given.

As described above using FIG. 2, the light-emitting element of thepresent invention has a structure in which holes are injected into thesecond layer 122 from the first layer 121. Therefore, it is preferablethat the difference in HOMO level between that of the organic compoundhaving a hole-transporting property and that of the organic compoundhaving an electron-transporting property be small. Further, since thelight-emitting element of the present invention has a structure in whichelectrons are injected into the first layer 121 from the second layer122, it is preferable that the difference in LUMO level between that ofthe organic compound having a hole-transporting property and that of theorganic compound having an electron-transporting property be small. Ifthe difference in HOMO level between that of organic compound having ahole-transporting property and that of the organic compound having anelectron-transporting property is large, the light-emitting region isformed more on the first layer side or on the second layer side.Similarly, if the difference in LUMO level between that of the organiccompound having a hole-transporting property and that of the organiccompound having an electron-transporting property is large, thelight-emitting region is formed more on the first layer side or on thesecond layer side. Accordingly, the difference between the HOMO level ofthe organic compound having a hole-transporting property and that of theorganic compound having an electron-transporting property is preferably0.3 eV or less, and more preferably, 0.1 eV or less. The differencebetween the LUMO level of the organic compound having ahole-transporting property and that of the organic compound having anelectron-transporting property is preferably 0.3 eV or less, and morepreferably, 0.1 eV or less.

Since light can be emitted from the light-emitting element byrecombination of electrons and holes, it is preferable that the organiccompound used for the light-emitting layer 113 be stable with respect torepetitive redox reactions. In other words, it is preferable that theorganic compound be able to be reversibly oxidized and reduced. Inparticular, it is preferable that the organic compound having ahole-transporting property and the organic compound having anelectron-transporting property be stable with respect to repetitiveredox reactions. Whether the organic compounds are stable with respectto repetitive redox reactions or not can be confirmed by cyclicvoltammetry (CV) measurements.

Specifically, whether the organic compounds are stable with respect torepetitive redox reactions or not can be confirmed by measurement ofchanges in the value of an oxidation peak potential (E_(pa)) of anoxidation reaction of the organic compound and the value of a reductionpeak potential (E_(pc)) of a reduction reaction, changes in the shape ofthe peaks, and the like. In the organic compound having ahole-transporting property and the organic compound having anelectron-transporting property which are used for the light-emittinglayer 113, the amount of change in the intensity of the oxidation peakpotential or the intensity of the reduction peak potential is preferablyless than 50%, and more preferably, less than 30%. In other words, forexample, where the oxidation peak decreases, the intensity of the peakis preferably kept at 50% or more, more preferably, 70%. In addition,the amount of change in the values of the oxidation peak potential andthe reduction peak potential is preferably 0.05 V or lower, morepreferably, 0.02 V or lower.

Furthermore, when the substance having a high light-emitting propertycontained in the first layer and the substance having a highlight-emitting property contained in the second layer are different,there is a possibility that light is emitted from only one of the firstlayer and the second layer. When the substance having a highlight-emitting property contained in the first layer and the substancehaving a high light-emitting property contained in the second layer arethe same, light can be made to be emitted in the vicinity of the centerof the light-emitting layer. Accordingly, it is preferred that thesubstance having a light-emitting property contained in the first layerand the substance having a light-emitting property contained in thesecond layer be the anthracene derivatives of the present invention.Since the anthracene derivatives of the present invention have highemission efficiency, by application thereof to the structure describedin this embodiment mode, a light-emitting element with high emissionefficiency and a long life can be obtained.

In the light-emitting element described in this embodiment mode, alight-emitting region is formed in the vicinity of the center of thelight-emitting layer, not at the interface between the light-emittinglayer and the hole-transporting layer or at the interface between thelight-emitting layer and the electron-transporting layer. Accordingly,the light-emitting element is not affected by deterioration caused bythe light-emitting region being close to the hole-transporting layer orthe electron-transporting layer. Therefore, the light-emitting elementwith little deterioration and a long life can be obtained. Furthermore,since the light-emitting layer in the light-emitting element of thepresent invention contains the compound that is stable with respect torepetitive redox reactions, there is little deterioration in thelight-emitting layer even if light emission by recombination of holesand electrons are repeated. Therefore, a light-emitting element with alonger life can be obtained.

Since the first organic compound and the second organic compound emitlight of similar colors, light with high color purity can be obtainedwith the light-emitting element described in this embodiment mode evenif not only the first organic compound but also the second organiccompound emits light. Further, since each of the anthracene derivativesof the present invention is a substance having a high light-emittingelement property which emits blue light the element structure describedin this embodiment mode is particularly effective for use in alight-emitting element of bluish color and a light-emitting element ofblue-greenish color. Blue color is needed for the fabrication of afull-color display, and the amount of deterioration can be reduced byapplication of the present invention. It is natural that the anthracenederivatives of the present invention may be used for a light-emittingelement of green or red color, as well. This embodiment mode can becombined with any other embodiment mode as appropriate.

[Embodiment Mode 7]

In this embodiment mode, a light-emitting element in which a pluralityof light-emitting units according to the present invention is stacked(hereinafter, referred to as a stacked type element) is described usingFIG. 3. This light-emitting element is a stacked type light-emittingelement that has a plurality of light-emitting units between a firstelectrode and a second electrode. Each light-emitting unit can have astructure similar to that of the layer 102 that contains an organiccompound described in Embodiment Mode 2. In other words, thelight-emitting element described in Embodiment Mode 2 is alight-emitting element that has one light-emitting unit. In thisembodiment mode, a light-emitting element that has a plurality oflight-emitting units is described.

In FIG. 3, a first light-emitting unit 511 and a second light-emittingunit 512 are stacked between a first electrode 501 and a secondelectrode 502, and a charge generation layer 513 is provided between thefirst light-emitting unit 511 and the second light-emitting unit 512.Electrodes similar to those described in Embodiment Mode 2 can beapplied for the first electrode 501 and the second electrode 502. Thefirst light-emitting unit 511 and the second light-emitting unit 512 mayhave structures that are the same or different from each other, and astructure similar to those described in any of Embodiment Modes 2 to 6can be employed.

The charge generation layer 513 contains a composite material of anorganic compound and a metal oxide. The composite material of an organiccompound and a metal oxide is described in Embodiment Modes 2 or 5 andcontains an organic compound and a metal oxide such as vanadium oxide,molybdenum oxide, or tungsten oxide. As the organic compound, a varietyof compounds such as aromatic amine compounds, carbazole derivatives,aromatic hydrocarbons, or compounds with a high molecular weight (suchas oligomers, dendrimers, or polymers) can be used. It is to be notedthat an organic compound having a hole mobility of greater than or equalto 10⁻⁶ cm²/(V·s) is preferably applied as the organic compound.However, a substance other than these compounds may also be used as longas it is a substance in which the hole-transporting property is higherthan the electron-transporting property. Since the composite material ofan organic compound and a metal oxide is superior in carrier-injectingproperty and carrier-transporting property, low-voltage driving andlow-current driving can be realized.

It is to be noted that the charge generation layer 513 may be formed bya combination of a composite material of an organic compound and a metaloxide with another material. For example, the charge generation layer513 may be formed by a combination of a layer containing the compositematerial of an organic compound and a metal oxide with a layercontaining one compound selected from among electron-donating substancesand a compound having a high electron-transporting property. Further,the charge generation layer 513 may be formed by a combination of alayer containing the composite material of an organic compound and ametal oxide with a transparent conductive film.

In any case, any structure for the charge generation layer 513interposed between the first light-emitting unit 511 and the secondlight-emitting unit 512 is acceptable as long as it is one by whichelectrons are injected into one light-emitting unit and holes areinjected into the other light-emitting unit when a voltage is appliedbetween the first electrode 501 and the second electrode 502. Forexample, an acceptable structure is one in which, in FIG. 3, the chargegeneration layer 513 injects electrons into the first light-emittingunit 511 and injects holes into the second light-emitting unit 512 whena voltage is applied so that the potential of the first electrode ishigher than that of the second electrode.

In this embodiment mode, the light-emitting element having twolight-emitting units is described; however, the present invention can beapplied in a similar manner to a light-emitting element in which threeor more light-emitting units are stacked. When a plurality oflight-emitting units are arranged to be partitioned from each other witha charge generation layer between a pair of electrodes, like thelight-emitting element according to this embodiment mode, emission froma region of high luminance can be realized at a low current density, andthus, an element with a long life can be achieved. For example, when thelight-emitting element is applied to a lighting device, a drop involtage due to the resistance of an electrode material can besuppressed, and thus, uniform emission in a large area can be achieved.In other words, a light-emitting device that can be driven at lowvoltage and has low power consumption can be realized.

When the emission color is different for each light-emitting unit, adesired emission color can be obtained from the whole light-emittingelement. For example, when an emission color of the first light-emittingunit and an emission color of the second light-emitting unit arecomplementary colors, it is possible to obtain a light-emitting elementhaving two light-emitting units, from which white light is emitted fromthe whole element. It is to be noted that the complementary colors referto colors that can produce an achromatic color when they are mixed. Thatis, white light emission can be obtained by mixture of light fromsubstances whose emission colors are complementary colors. Similarly ina light-emitting element having three light-emitting units, for example,white light can be obtained from the whole light-emitting element whenemission colors of the first, second, and third light-emitting units arered, green, and blue, respectively.

This embodiment mode can be combined with any other embodiment mode asappropriate.

[Embodiment Mode 8]

In this embodiment mode, a light-emitting device manufactured using anyof the anthracene derivatives of the present invention is described.

In this embodiment mode, a light-emitting device manufactured using anyof the anthracene derivatives of the present invention is describedusing FIGS. 4A and 4B. FIG. 4A is a top view of a light-emitting device,and FIG. 4B is a cross-sectional view taken along lines A-A′ and B-B′ ofFIG. 4A. The light-emitting device has a driver circuit portion (asource side driver circuit) 401, a pixel portion 402, and a drivercircuit portion (a gate side driver circuit) 403 which are indicated bydotted lines to control the light-emitting device. Reference numerals404 and 405 denote a sealing substrate and a sealing material,respectively. A portion enclosed by the sealing material 405 correspondsto a space 407.

A lead wiring 408 is a wiring used to transmit signals to be inputted tothe source side driver circuit 401 and the gate side driver circuit 403and receives a video signal, a clock signal, a start signal, a resetsignal, and the like from a flexible printed circuit (FPC) 409 which isan external input terminal. It is to be noted that only the FPC isillustrated in this case; however, the FPC may be provided with aprinted wiring board (PWB). The category of the light-emitting device inthis specification includes not only a light-emitting device itself butalso a light-emitting device to which an FPC or a PWB is attached with.

Next, a cross-sectional structure is described using FIG. 4B. The drivercircuit portion and the pixel portion are formed over an elementsubstrate 410. In this case, one pixel in the pixel portion 402 and thesource side driver circuit 401 which is the driver circuit portion areillustrated.

A CMOS circuit, which is a combination of an n-channel TFT 423 and ap-channel TFT 424, is formed as the source side driver circuit 401. Eachdriver circuit portion may be any of a variety of circuits such as aCMOS circuit, a PMOS circuit, or an NMOS circuit. Although adriver-integration type device, in which a driver circuit is formed overthe substrate over which the pixel portion is provided, is described inthis embodiment mode, a driver circuit needed not necessarily be formedover the substrate over which the pixel portion is provided but can beformed externally from a substrate.

The pixel portion 402 is formed of a plurality of pixels each of whichincludes a switching TFT 411, a current control TFT 412, and a firstelectrode 413 which is electrically connected to a drain of the currentcontrol TFT 412. It is to be noted that an insulator 414 is formed tocover end portions of the first electrode 413. In this case, theinsulator 414 is formed using a positive photosensitive acrylic resinfilm.

The insulator 414 is formed so as to have a curved surface havingcurvature at an upper end portion or a lower end portion thereof inorder to make the coverage favorable. For example, in the case of usingpositive photosensitive acrylic as a material for the insulator 414, itis preferable that the insulator 414 be formed so as to have a curvedsurface with radius of curvature (0.2 μm to 3 μm) only at the upper endportion thereof. The insulator 414 can be formed using either a negativetype which becomes insoluble in an etchant by light irradiation or apositive type which becomes soluble in an etchant by light irradiation.

A layer 416, which contains an organic compound, and a second electrode417 are formed over the first electrode 413. In this case, it ispreferred that the first electrode 413 serving as an anode be formedusing a material with a high work function. For example, the firstelectrode 413 can be formed using a single-layer film of an ITO film, anindium tin oxide film containing silicon, an indium oxide filmcontaining 2 wt % to 20 wt % of zinc oxide, a titanium nitride film, achromium film, a tungsten film, a Zn film, a Pt film, or the like; astack of a titanium nitride film and a film containing aluminum as itsmain component; or a stacked film such as a film having a three-layerstructure of a titanium nitride film, a film containing aluminum as itsmain component, and another titanium nitride film. When the firstelectrode 413 has a stacked structure, resistance as a wiring is low, agood ohmic contact is formed, and further, the first electrode 413 canbe made to function as an anode.

The layer 416 containing an organic compound is formed by any of avariety of methods such as a deposition method using a deposition mask,an inkjet method, and a spin coating method. The layer 416 containing anorganic compound contains any of the anthracene derivatives of thepresent invention which are described in Embodiment Mode 1. Further,another material of the layer 416 containing an organic compound be anyof compounds with a low molecular weight or compounds with a highmolecular weight (the category of the compounds with a high molecularweight includes oligomers and dendrimers). Further, the material of thelayer containing an organic compound may be not only an organic compoundbut also an inorganic compound.

As a material used for the second electrode 417 which is formed over thelayer 416 containing an organic compound and serves as a cathode, it ispreferable to use a material with a low work function (e.g., Al, Mg, Li,Ca, or an alloy or compound thereof such as MgAg, Mg—In, Al—Li, LiF, orCaF₂). When light generated in the layer 416 containing an organiccompound is transmitted through the second electrode 417, the secondelectrode 417 may be formed of a stack of a metal thin film and atransparent conductive film (e.g., a film of ITO, indium oxidecontaining 2 wt % to 20 wt % of zinc oxide, indium tin oxide containingsilicon or silicon oxide, or zinc oxide (ZnO)).

The sealing substrate 404 is attached using the sealing material 405 tothe element substrate 410; thus, a light-emitting element 418 isprovided in the space 407 enclosed by the element substrate 410, thesealing substrate 404, and the sealing material 405. It is to be notedthat the space 407 is filled with a filler. The space 407 is filled withan inert gas (e.g., nitrogen or argon) or the sealing material 405 insome cases.

It is preferable that an epoxy-based resin be used to form the sealingmaterial 405 and that such a material permeate little moisture andoxygen as much as possible. In addition to a glass substrate or a quartzsubstrate, the sealing substrate 404 can be formed of a plasticsubstrate made of fiberglass-reinforced plastic (FRP), polyvinylfluoride (PVF), polyester, acrylic, or the like.

Accordingly, a light-emitting device manufactured using any of theanthracene derivatives of the present invention can be obtained.

Since any of the anthracene derivatives described in Embodiment Mode 1is used in the light-emitting device of the present invention, alight-emitting device having favorable characteristics can be obtained.Specifically, a light-emitting device that has a long life can beobtained.

Further, since the anthracene derivatives of the present invention havehigh emission efficiency, a light-emitting device having low powerconsumption can be provided.

Further, since the light-emitting element in which any of the anthracenederivatives of the present invention is used can emit blue light withhigh color purity at high efficiency, the anthracene derivatives aresuitable for use in full-color displays. Further, since thelight-emitting element in which any of the anthracene derivatives of thepresent invention is used can emit blue light for a long period of timeand has low power consumption, the anthracene derivatives are suitablefor use in full-color displays.

Although, as described above, an active matrix light-emitting device inwhich driving of a light-emitting element is controlled by transistorsis described in this embodiment, the light-emitting device may also be apassive matrix light-emitting device. FIGS. 5A and 5B show a passivematrix light-emitting device to which the present invention is applied.FIG. 5A is a perspective view of the light-emitting device, and FIG. 5Bis a cross-sectional view taken along a line X-Y of FIG. 5A. In FIGS. 5Aand 5B, a layer 955 containing an organic compound is provided betweenan electrode 952 and an electrode 956 over a substrate 951. End portionsof the electrode 952 are covered by an insulating layer 953. Then, apartition layer 954 is provided over the insulating layer 953. Asidewall of the partition layer 954 slopes so that the distance betweenone sidewall and another sidewall becomes narrower toward the substratesurface. In other words, a cross section taken in the direction of theshort side of the partition layer 954 is trapezoidal, and the base ofthe cross-section (a side facing in the same direction as a planedirection of the insulating layer 953 and in contact with the insulatinglayer 953) is shorter than the upper side thereof (a side facing in thesame direction as the plane direction of the insulating layer 953 andnot in contact with the insulating layer 953). The partition layer 954provided in this manner can be used to prevent the light-emittingelement from being defective due to static electricity or the like. Evenin the case of a passive matrix light-emitting device, when thelight-emitting device includes the light-emitting element of the presentinvention, a light-emitting device with a long life can be obtained, anda light-emitting device having low power consumption can also beobtained.

[Embodiment Mode 9]

In this embodiment mode, electronic devices of the present inventionthat include the light-emitting device described in Embodiment Mode 8are described. The electronic devices of the present invention eachcontain any of the anthracene derivatives described in Embodiment Mode 1and have a display portion that has a long life. Further, the electronicdevices of the present invention each have a display portion in whichpower consumption is reduced.

Examples of electronic devices that include light-emitting elementsfabricated using any of the anthracene derivatives of the presentinvention include cameras such as video cameras or digital cameras,goggle type displays, navigation systems, audio playback devices (e.g.,car audio systems and audio systems), computers, game machines, portableinformation terminals (e.g., mobile computers, cellular phones, portablegame machines, and electronic books), image playback devices in which arecording medium is provided (devices that are capable of playing backrecording media such as digital versatile discs (DVDs) and equipped witha display device that can display the image), and the like. Specificexamples of these electronic devices are shown in FIGS. 6A to 6D.

FIG. 6A shows a television device according to the present inventionwhich includes a housing 9101, a support stand 9102, a display portion9103, a speaker portion 9104, a video input terminal 9105, and the like.In the television device, the display portion 9103 has light-emittingelements similar to those described in Embodiment Modes 2 to 7 arrangedin matrix form. The light-emitting element is characterized by havinghigh emission efficiency and a long life. Since the display portion 9103formed of the light-emitting elements has similar characteristics, imagequality does not deteriorate much and lower power consumption isachieved in the television device. Such characteristics contribute to asignificant reduction in size and number of the deteriorationcompensation function circuits and power supply circuits in thetelevision device, whereby the size and weight of the housing 9101 andsupport stand 9102 can be reduced. In the television device according tothe present invention, lower power consumption, a higher image quality,a smaller size, and a lighter weight are achieved; therefore, productssuitable for a residence can be provided. Also, since the anthracenederivatives described in Embodiment Mode 1 can emit blue light with highcolor purity, full-color display is possible, and a television devicehaving a display portion with a long life can be obtained.

FIG. 6B shows a computer according to the present invention whichincludes a main body 9201, a housing 9202, a display portion 9203, akeyboard 9204, an external connection port 9205, a pointing device 9206,and the like. In the computer, the display portion 9203 haslight-emitting elements similar to those described in Embodiment Modes 2to 7 arranged in matrix form. The light-emitting element ischaracterized by having high emission efficiency and a long life. Sincethe display portion 9203 formed of the light-emitting elements hassimilar characteristics, image quality does not deteriorate much andlower power consumption is achieved in the computer. Suchcharacteristics contribute to a significant reduction in size and numberof the deterioration compensation function circuits and power supplycircuits in the computer, whereby the size and weight of the main body9201 and the housing 9202 can be reduced. In the computer according tothe present invention, lower power consumption, a higher image quality,a smaller size, and a lighter weight are achieved; therefore, productssuitable for the environment can be supplied. Further, since theanthracene derivatives described in Embodiment Mode 1 can emit bluelight with high color purity, full-color display is possible, and acomputer having a display portion with a long life can be obtained.

FIG. 6C shows a cellular phone according to the present invention whichincludes a main body 9401, a housing 9402, a display portion 9403, anaudio input portion 9404, an audio output portion 9405, operation keys9406, an external connection port 9407, an antenna 9408, and the like.In the cellular phone, the display portion 9403 has light-emittingelements similar to those described in Embodiment Modes 2 to 7 arrangedin matrix form. The light-emitting element is characterized by highemission efficiency and a long life. Since the display portion 9403formed of the light-emitting elements has similar characteristics, imagequality does not deteriorate much and lower power consumption isachieved in the cellular phone. Such characteristics contribute to asignificant reduction in size and number of the deteriorationcompensation function circuits and power supply circuits in the cellularphone, whereby the size and weight of the main body 9401 and the housing9402 can be reduced. In the cellular phone according to the presentinvention, lower power consumption, a higher image quality, a smallersize, and a lighter weight are achieved; therefore, products suitablefor portability can be provided. Since the anthracene derivativesdescribed in Embodiment Mode 1 can emit blue light with high colorpurity, full-color display is possible, and a cellular phone having adisplay portion with a long life can be obtained.

FIG. 6D shows a camera according to the present invention which includesa main body 9501, a display portion 9502, a housing 9503, an externalconnection port 9504, a remote control receiver 9505, an image receiver9506, a battery 9507, an audio input portion 9508, operation keys 9509,an eye piece portion 9510, and the like. In the camera, the displayportion 9502 has light-emitting elements similar to those described inEmbodiment Modes 2 to 7 arranged in matrix form. Some features of thelight-emitting element are its high emission efficiency and a long life.Since the display portion 9502 formed of the light-emitting elements hassimilar characteristics, image quality does not deteriorate much andlower power consumption can be achieved in the camera. Suchcharacteristics contribute to a significant reduction in size and numberof the deterioration compensation function circuits and power supplycircuits in the camera, whereby the size and weight of the main body9501 can be reduced. In the camera according to the present invention,lower power consumption, a higher image quality, a smaller size, and alighter weight are achieved; therefore, products suitable for beingcarried can be provided. Since the anthracene derivatives described inEmbodiment Mode 1 can emit blue light with high color purity, full-colordisplay is possible, and a camera having a display portion with a longlife can be obtained.

As described above, the applicable range of the light-emitting device ofthe present invention is extremely wide so that this light-emittingdevice can be applied to electronic devices of a variety of fields. Byuse of the anthracene derivatives of the present invention, anelectronic device that has a display portion with a long life can beobtained. Furthermore, by use of the anthracene derivatives of thepresent invention, an electronic device that has a display portion inwhich power consumption is reduced can be obtained.

Such a light-emitting device of the present invention can also be usedas a lighting device. One mode in which the light-emitting device of thepresent invention is used as a lighting device is described using FIG.7.

FIG. 7 shows an example of a liquid crystal display in which thelight-emitting device of the present invention is used as a backlight.The liquid crystal display device shown in FIG. 7 includes a housing901, a liquid crystal layer 902, a backlight 903, and a housing 904. Theliquid crystal layer 902 is connected to a driver IC 905. Thelight-emitting device of the present invention is used as the backlight903, and current is supplied through a terminal 906.

By use of the light-emitting device of the present invention as thebacklight of the liquid crystal display device, a backlight with highemission efficiency and lower power consumption and can be obtained.Since the light-emitting device of the present invention is a lightingdevice with plane light emission and can have a larger area, thebacklight can have a larger area, and a liquid crystal display devicecan also have a larger area. Furthermore, since the light-emittingdevice of the present invention is thin and has low power consumption, athinner shape and lower power consumption can also be achieved in adisplay device. Since the light-emitting device of the present inventionhas a long life, a liquid crystal display device in which thelight-emitting device of the present invention is used can also have along life.

FIG. 8 shows an example in which the light-emitting device to which thepresent invention is applied is used as a table lamp that is a lightingdevice. The table lamp shown in FIG. 8 has a housing 2001 and a lightsource 2002. The light-emitting device of the present invention is usedas the light source 2002. Since the light-emitting device of the presentinvention has high emission efficiency and a long life, the table lampalso has high emission efficiency and a long life.

FIG. 9 shows an example in which a light-emitting device to which thepresent invention is applied is used as an indoor lighting device 3001.Since the light-emitting device of the present invention can also have alarger area, the light-emitting device of the present invention can beused as a lighting device having a large emission area. Further, sincethe light-emitting device of the present invention is thin and has lowpower consumption, the light-emitting device of the present inventioncan be used as a lighting device with a thinner shape and lower powerconsumption. A television device 3002 according to the present inventionas described in FIG. 6A is placed in a room in which a light-emittingdevice to which the present invention is applied is used as the indoorlighting device 3001, and public broadcasting and movies can be enjoyed.In such a case, since power consumption is low in both devices, apowerful image can be watched in a bright room without any concern aboutcharges for electricity.

EXAMPLE 1

In this synthesis example, a synthesis method of an anthracenederivative4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPA) of the present invention represented by a structural formula(100) is described in specific terms.

[Step 1: Synthesis of 9-phenyl-9H-carbazole-3-boronic acid]

Into a 500 mL three-neck flask were put 10 g (31 mmol) of3-bromo-9-phenyl-9H-carbazole. The air in the flask was replaced withnitrogen. 150 mL of tetrahydrofuran (THF) were put into the flask, and3-bromo-9-phenyl-9H-carbazole was dissolved therein. This solution wascooled to −80° C. Into this solution were dripped 20 mL (32 mmol) ofn-butyllithium (a 1.58 mol/L hexane solution) with the use of a syringe.After the dripping was completed, this solution was stirred at the sametemperature for 1 hour. After the stirring, 3.8 mL (34 mmol) oftrimethyl borate were added to the solution, and the solution wasstirred for about 15 hours while the temperature of the solution wasbeing brought back to room temperature. Thereafter, about 150 mL (1.0mol/L) of dilute hydrochloric acid were added to the solution, and thenthe solution was stirred for 1 hour. After the stirring, an aqueouslayer of the mixture (vas extracted with ethyl acetate. The extract wascombined with an organic layer and then washed with a saturated sodiumhydrogen carbonate solution. The organic layer was dried with magnesiumsulfate. After the drying, the mixture was subjected to gravityfiltration. The obtained filtrate was condensed to give an oily lightbrown substance. The obtained oily substance was dried under reducedpressure to give 7.5 g of a light brown solid, which was the object ofthe synthesis, at a yield of 86%. A synthesis scheme of Step 1 is shownin (b-1) given below.

[Step 2: Synthesis of 4-(9-phenyl-9H-carbazol-3-yl)diphenylamine (PCBA)]

Into a 500 mL three-neck flask were put 6.5 g (26 mmol) of4-bromo-diphenylamine, 7.5 g (26 mmol) of9-phenyl-9H-carbazole-3-boronic acid, and 400 mg (1.3 mmol) oftri(o-tolyl)phosphine. The air in the flask was replaced with nitrogen.To the mixture were added 100 mL of toluene, 50 mL of ethanol, and 14 mL(0.2 mol/L) of an aqueous solution of potassium carbonate. Under reducedpressure, this mixture was degassed while being stirred. After thedegassing, 67 mg (30 mmol) of palladium(II) acetate were added to themixture. This mixture was refluxed at 100° C. for 10 hours. After thereflux, an aqueous layer of the mixture was extracted with toluene, andthe extract was combined with an organic layer and then washed with asaturated saline solution. The organic layer was dried with magnesiumsulfate. After the drying, this mixture was subjected to gravityfiltration. The obtained filtrate was condensed to give an oily lightbrown substance. This oily substance was purified by silica gel columnchromatography (a developing solvent was a mixed solvent ofhexane:toluene=4:6). A white solid obtained after the purification wasrecrystallized with dichloromethane/hexane to give 4.9 g of a whitesolid, which was the object of the synthesis, at a yield of 45%. Asynthesis scheme of Step 2 is shown in (b-2) given below.

The solid obtained in the above Step 2 was analyzed by nuclear magneticresonance measurements (¹H NMR). The measurement results are describedbelow, and the ¹H NMR chart is shown in FIGS. 10A and 10B. It is to benoted that FIG. 10B is a chart showing an enlarged view of the range of6.0 ppm to 9.0 ppm in FIG. 10A. From the measurement results, it can beseen that the organic compound PCBA of the present invention which is asource material used for the synthesis of the anthracene derivative ofthe present invention represented by the above structural formula (100)was obtained.

¹H NMR (DMSO-d₆, 300 MHz): δ=6.81-6.86 (m, 1H), 7.12 (dd, J₁=0.9 Hz,J₂=8.7 Hz, 2H), 7.19 (d, J=8.7 Hz, 2H), 7.23-7.32 (m, 3H), 7.37-7.47 (m,3H), 7.51-7.57 (m, 1H), 7.61-7.73 (m, 7H) 8.28 (s, 1H), 8.33 (d, J=7.2Hz, 1H), 8.50 (d, J=1.5 Hz, 1H)

[Step 3: Synthesis of PCBAPA]

Into a 300 mL three-neck flask were put 7.8 g (12 mmol) of9-(4-bromophenyl)-10-phenylanthracene, 4.8 g (12 mmol) of PCBA, and 5.2g (52 mmol) of sodium tert-butoxide. The air in the flask was replacedwith nitrogen. To the mixture were added 60 mL of toluene and 0.30 mL oftri(tert-butyl)phosphine (a 10 wt % hexane solution). Under reducedpressure, this mixture was degassed while being stirred. After thedegassing, 136 mg (0.24 mmol) of bis(dibenzylideneacetone)palladium(0)were added to the mixture. This mixture was stirred at 100° C. for 3hours. After the stirring, about 50 mL of toluene were added to thismixture. The mixture was subjected to suction filtration through celite(produced by Wako Pure Chemical Industries, Ltd., Catalog No.531-16855), alumina, and Florisil (produced by Wako Pure ChemicalIndustries, Ltd., Catalog No. 540-00135). The obtained filtrate wascondensed to give a yellow solid. This solid was recrystallized withtoluene/hexane to give 6.6 g of a light yellow powdered solid PCBAPA,which was the object of the synthesis, at a yield of 75%. Then, 3.0 g ofthe obtained light yellow powdered solid were purified by trainsublimation. For sublimation purification conditions, PCBAPA was heatedat 350° C. under a pressure of 8.7 Pa with a flow rate of argon gas of3.0 mL/min. After the sublimation purification, 2.7 g of a light yellowsolid PCBAPA was obtained at a yield of 90%. A synthesis scheme of Step3 is shown in (b-3) given below.

The solid obtained in the above Step 3 was analyzed by ¹H NMR. Themeasurement results are described below, and the ¹H NMR chart is shownin FIGS. 11A and 11B. It is to be noted that FIG. 11B is a chart showingan enlarged view of the range of 7.0 to 8.5 ppm in FIG. 11A. From themeasurement results, it can be seen that the anthracene derivativePCBAPA of the present invention represented by the above structuralformula (100) was obtained.

¹H NMR (CDCl₃, 300 MHz): δ=7.09-7.14 (m, 1H), 7.28-7.72 (m, 33H), 7.88(d, J=8.4 Hz, 2H), 8.19 (d, J=7.2 Hz, 1H), 8.37 (d, J=1.5 Hz, 1H)

Next, an absorption spectrum of PCBAPA was measured using anultraviolet-visible spectrophotometer (V-550, manufactured by JASCOCorporation) at room temperature with the use of a toluene solution.Further, an emission spectrum of PCBAPA was measured using afluorescence spectrophotometer (FS920, manufactured by HamamatsuPhotonics Corporation) at room temperature with the use of a toluenesolution. The measurement results are shown in FIG. 12. Further, PCBAPAwas deposited by a deposition method, and a thin film of PCBAPA wasmeasured in a similar manner. The measurement results are shown in FIG.13. In each of FIG. 12 and FIG. 13, the horizontal axis indicates thewavelength (nm), and the vertical axis indicates the absorptionintensity (arbitrary unit) and the emission intensity (arbitrary unit).

From FIG. 12 and FIG. 13, it can be seen that the toluene solution ofPCBAPA has an emission peak at 459 nm, and the thin film thereof has anemission peak at 473 nm. Thus, it is found that PCBAPA emits blue lightwith high color purity.

EXAMPLE 2

In this example, a light-emitting element of the present invention isdescribed using FIG. 14. Chemical formulae of materials used in thisexample are shown below.

(Light-Emitting Element 1)

First, indium tin oxide containing silicon oxide was deposited over aglass substrate 1100 by a sputtering method, whereby a first electrode1101 was formed. It is to be noted that the film thickness of the firstelectrode was set to be 110 nm and that the area of the electrode wasset to be 2 mm×2 mm.

Next, the substrate over which the first electrode was formed was fixedto a substrate holder provided in a vacuum deposition apparatus so thata surface on which the first electrode was formed faced downward. Afterthe pressure of the vacuum deposition apparatus was reduced to about10⁻⁴ Pa, a layer 1102 containing a composite material of an organiccompound and an inorganic compound was formed over the first electrode1101 by co-deposition of NPB and molybdenum(VI) oxide. The filmthickness of the layer 1102 was set to be 50 nm, and the weight ratio ofNPB and molybdenum(VI) oxide was adjusted so as to be 4:1(=NPB:molybdenum oxide). It is to be noted that the co-deposition methodis a deposition method in which deposition is performed from a pluralityof evaporation sources at the same time in one treatment chamber.

Next, NPB was deposited to a thickness of 10 nm over the layer 1102containing a composite material by a deposition method using resistiveheating, whereby a hole-transporting layer 1103 was formed.

Further, by co-deposition of9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (CzPA) and PCBAPA, alight-emitting layer 1104 was formed over the hole-transporting layer1103 to a thickness of 30 nm. The weight ratio of CzPA and PCBAPA wasadjusted so as to be 1:0.10 (=CzPA:PCBAPA).

Thereafter, tris(8-quinolinolato)aluminum (Alq) was deposited to athickness of 10 nm over the light-emitting layer 1104 by a depositionmethod using resistive heating, whereby an electron-transporting layer1105 was formed.

Further, by co-deposition of tris(8-quinolinolato)aluminum (Alq) andlithium, an electron-injecting layer 1106 was formed to a thickness of20 nm over the electron-transporting layer 1105. The weight ratio of Alqand lithium was adjusted so as to be 1:0.01 (=Alq:lithium).

Lastly, aluminum was deposited to a thickness of 200 nm over theelectron-injecting layer 1106 by a deposition method using resistiveheating, whereby a second electrode 1107 was formed. Accordingly, alight-emitting element 1 was fabricated.

Current density-luminance characteristics, voltage-luminancecharacteristics, luminance-current efficiency characteristics, andluminance-external quantum efficiency of the light-emitting element 1are shown in FIG. 15, FIG. 16, FIG. 17, and FIG. 18, respectively. Also,the emission spectrum measured at a current of 1 mA is shown in FIG. 19.From FIG. 19, it can be seen that light emitted from the light-emittingelement was from PCBAPA. A CIE chromaticity coordinates of thelight-emitting element 1 at luminance of 820 cd/m² were (x, y)=(0.16,0.19), which are indicative of blue light with high color purity. As canbe seen from FIG. 18, the external quantum efficiency of thelight-emitting element 1 measured at luminance of 820 cd/m² was 2.9%,which is indicative of high external quantum efficiency. Thus, thelight-emitting element 1 has high emission efficiency. From FIG. 17, itcan be seen that the current efficiency of the light-emitting element 1measured at luminance of 820 cd/m² was 4.2 cd/A, which is indicative ofhigh luminous efficiency. From FIG. 16, the driving voltage of thelight-emitting element 1 measured at luminance of 820 cd/m² was 5.2 V,and a voltage needed to obtain a given luminance is low. Thus, it isfound that power consumption for the light-emitting element 1 is low.

In addition, when the light-emitting element 1 of this example wasdriven under conditions of an initial luminance set to 1000 cd/m2 and aconstant instant current density, luminance after 380 hours was retainedat 81% of the initial luminance. The results are shown in FIG. 26. InFIG. 26, the horizontal axis indicates time (h), and the vertical axisindicates normalized luminance where the initial luminance was 100%.Consequently, it is found that a light-emitting element with littledeterioration and a long life can be obtained by application of thepresent invention.

EXAMPLE 3

In this example, a light-emitting element of the present invention isdescribed using FIG. 20. Chemical formulae of materials used in thisexample are shown below.

(Light-Emitting Element 2)

First, indium tin oxide containing silicon oxide was deposited over aglass substrate 2100 by a sputtering method, whereby a first electrode2101 was formed. It is to be noted that the film thickness of the firstelectrode was set to be 110 nm and that the area of the electrode wasset to be 2 mm×2 mm.

Next, the substrate over which the first electrode was formed was fixedto a substrate holder provided in a vacuum deposition apparatus so thata surface on which the first electrode was formed faced downward. Afterthe pressure of the vacuum deposition apparatus was reduced to about10⁻⁴ Pa, a layer 2102 containing a composite material of an organiccompound and an inorganic compound was formed over the first electrode2101 by co-deposition of NPB and molybdenum(VI) oxide. The filmthickness of the layer 2102 was set to be 50 nm, and the weight ratio ofNPB and molybdenum(VI) oxide was adjusted so as to be 4:1(═NPB:molybdenum oxide). It is to be noted that the co-deposition methodis a deposition method in which deposition is performed from a pluralityof evaporation sources at the same time in one treatment chamber.

Next, NPB was deposited over the layer 2102 containing a compositematerial to a thickness of 10 nm by a deposition method using resistiveheating, whereby a hole-transporting layer 2103 was formed.

Further, by co-deposition of 9,10-diphenylanthracene (DPAnth) and theanthracene derivative PCBAPA of the present invention, a first layer2121 was formed over the hole-transporting layer 2103 to a thickness of30 nm. The weight ratio of DPAnth and PCBAPA was adjusted so as to be1:0.05 (=DPAnth:PCBAPA).

Further, by co-deposition of9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (CzPA) and the anthracenederivative PCBAPA of the present invention, a second layer 2122 wasformed over the first layer 2121 to a thickness of 30 nm. The weightratio of CzPA and PCBAPA was adjusted so as to be 1:0.10 (=CzPA:PCBAPA).

Thereafter, tris(8-quinolinolato)aluminum (Alq) was deposited over thesecond layer 2122 to a thickness of 10 nm by a deposition method usingresistive heating, whereby an electron-transporting layer 2104 wasformed.

Further, by co-deposition of tris(8-quinolinolato)aluminum (Alq) andlithium, an electron-injecting layer 2105 was formed over theelectron-transporting layer 2104 to a thickness of 20 nm. The weightratio of Alq and lithium was adjusted so as to be 1:0.01 (=Alq:lithium).

Lastly, aluminum was deposited over the electron-injecting layer 2105 toa thickness of 200 nm by a deposition method using resistive heating,whereby a second electrode 2106 was formed. Accordingly, alight-emitting element 2 was fabricated.

Current density-luminance characteristics, voltage-luminancecharacteristics, luminance-current efficiency characteristics, andluminance-external quantum efficiency of the light-emitting element 2are shown in FIG. 21, FIG. 22, FIG. 23, and FIG. 24, respectively. Also,the emission spectrum measured at a current of 1 mA is shown in FIG. 25.From FIG. 25, it can be seen that light emitted from the light-emittingelement was from PCBAPA. A CIE chromaticity coordinates of thelight-emitting element 2 at luminance of 990 cd/m² were (x, y)=(0.15,0.17), which are indicative of blue light with high color purity. As canbe seen from FIG. 24, the external quantum efficiency of thelight-emitting element 2 measured at luminance of 990 cd/m² was 3.3%which is indicative of high external quantum efficiency. Thus, thelight-emitting element 2 has high emission efficiency. From FIG. 23, itcan be seen that the current efficiency of the light-emitting element 2measured at luminance of 990 cd/m² was 4.1 cd/A, which is indicative ofhigh luminous efficiency. From FIG. 22, the driving voltage of thelight-emitting element 2 measured at luminance of 990 cd/m² was 6.4 V,and a voltage needed to obtain a given luminance is low. Thus, it isfound that power consumption for the light-emitting element 2 is low.

In addition, when the light-emitting element 1 of this example wasdriven under conditions of an initial luminance set to 1000 cd/m2 and aconstant instant current density, luminance after 380 hours was retainedat 81% of the initial luminance. The results are shown in FIG. 27. InFIG. 27, the horizontal axis indicates time (h) and the vertical axisindicates normalized luminance where the initial luminance was 100%.Consequently, it is found that a light-emitting element with littledeterioration and a long life can be obtained by application of thepresent invention.

EXAMPLE 4

In this example, a synthesis method of an anthracene derivative4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPBA) of the present invention represented by a structural formula(300) is described in specific terms.

[Step 1: Synthesis of 9-(4′-bromobiphenyl-4-yl)-10-phenylanthracene]

Into a 100 mL three-neck flask were put 2.8 g (7.2 mmol) of9-iodine-10-phenylanthracene and 1.5 g (7.2 mmol) of4′-bromobiphenyl-4-boronic acid. The air in the flask was replaced withnitrogen. To the mixture were added 40 mL of toluene and 10 mL (2.0mol/L) of an aqueous solution of sodium carbonate. This mixture wasstirred to be degassed while the pressure was being reduced. After thedegassing, 120 mg (0.10 mmol) oftetrakis(triphenylphosphine)palladium(0) were added to the mixture. Thismixture was stirred at 90° C. for 4 hours. After the stirring, about 50mL of toluene were added to this mixture. The mixture was subjected tosuction filtration through alumina, celite (produced by Wako PureChemical Industries, Ltd., Catalog No. 531-16855), and Florisil(produced by Wako Pure Chemical Industries, Ltd., Catalog No.540-00135). The solid obtained by condensation of the obtained filtratewas purified by high-performance liquid chromatography (a mobile phase:chloroform) to give a light yellow solid. The obtained solid wasrecrystallized with chloroform/hexane to give 1.4 g of a light yellowpowdered solid, which was the object of the synthesis, at a yield of40%. A synthesis scheme of Step 1 is shown in (c-1) given below.

[Step 2: Synthesis of4-[4-(10-phenyl-9-anthryl)phenyl]-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine(PCBAPBA)]

Into a 50 mL three-neck flask were put 1.0 g (2.1 mmol) of9-(4′-bromobiphenyl-4-yl)-10-phenylanthracene, 845 mg (2.1 mmol) of4-(9-phenyl-9H-carbazol-3-yl)diphenylamine (PCBA), and 1.0 g (10 mmol)sodium tert-butoxide. The air in the flask was replaced with nitrogen.To the mixture were added 15 mL of toluene and 0.10 mL oftri(tert-butyl)phosphine (a 10 wt % hexane solution). Under reducedpressure, this mixture was degassed while being stirred. After thedegassing, 58 mg (0.10 mmol) of bis(dibenzylideneacetone)palladium(0)were added to the mixture. This mixture was stirred at 100° C. for 5hours. After the stirring, the temperature of the mixture was cooled toroom temperature, and then about 20 mL of toluene were added to themixture. The mixture was subjected to filtration through Florisil(produced by Wako Pure Chemical Industries, Ltd., Catalog No.540-00135), celite (produced by Wako Pure Chemical Industries, Ltd.,Catalog No. 531-16855), and alumina. The obtained filtrate was condensedto give a light yellow solid. This obtained solid was recrystallizedwith toluene/hexane to give 1.5 g of a light yellow powdered solid,which was the object of the synthesis, at a yield of 90% A synthesisscheme of Step 2 is shown in (c-2) given below.

Then, 1.1 g of the obtained light yellow powdered solid was purified bytrain sublimation. For sublimation purification conditions, PCBAPBA washeated at 380° C. under a pressure of 6.0 Pa with a flow rate of argongas of 3.0 mL/min. After the sublimation purification, 1.0 g of a lightyellow solid was obtained at a yield of 93%.

The obtained solid was analyzed by ¹H NMR. The measurement results aredescribed below, and the ¹H NMR chart is shown in FIGS. 28A and 28B. Itis to be noted that FIG. 28B is a chart showing an enlarged view of therange of 7.0 to 8.5 ppm in FIG. 28A. From the measurement results, itcan be seen that the anthracene derivative PCBAPBA of the presentinvention represented by the above structural formula (300) wasobtained.

¹H NMR (DMSO-d₆, 300 MHz): δ=7.09-7.12 (m, 1H), 7.25-7.31 (m, 12H),7.34-7.79 (m, 23H), 7.80-7.85 (m, 4H), 8.20 (d, J=7.8 Hz, 1H), 8.36 (d,J=1.5 Hz, 1H)

Further, thermogravimetry-differential thermal analysis (TG-DTA) ofPCBAPBA was carried out using a high vacuum differential typedifferential thermal balance (TG-DTA2410SA, manufactured by Bruker AXSK.K.). The measurement was performed under normal pressure in a streamof nitrogen (at a flow rate of 200 mL/min) at a rate of temperatureincrease of 10° C./min. From the relationship between the weight and thetemperature (thermogravimetry), it was understood that a 5% weightreduction was seen at temperatures of more than 500° C., which isindicative of high thermal stability.

Next, an absorption spectrum of PCBAPBA was measured using anultraviolet-visible spectrophotometer (V-550, manufactured by JASCOCorporation) at room temperature with the use of a toluene solution. Themeasurement results are shown in FIG. 29. In FIG. 29, the horizontalaxis indicates the wavelength (nm) and the vertical axis indicates theabsorption intensity (arbitrary unit). Further, an emission spectrum ofPCBAPBA was measured using a fluorescence spectrophotometer (FS920,manufactured by Hamamatsu Photonics Corporation) at room temperaturewith the use of a toluene solution. The measurement results are shown inFIG. 30. In FIG. 30, the horizontal axis indicates the wavelength (nm)and the vertical axis indicates the emission intensity (arbitrary unit).Absorption of the toluene solution of PCBAPBA was seen at around 373 nmand around 395 nm. The maximum emission wavelength of the toluenesolution was 440 nm (an excitation wavelength of 370 nm).

Further, PCBAPBA was deposited by a deposition method, and a thin filmof PCBAPA was measured in a similar manner. An absorption spectrum ofthe thin film of PCBAPA is shown in FIG. 31, and an emission spectrumthereof is shown in FIG. 32. In FIG. 31, the horizontal axis indicatesthe wavelength (nm) and the vertical axis indicates the absorptionintensity (arbitrary unit). In FIG. 32, the horizontal axis indicatesthe wavelength (nm) and the vertical axis indicates the emissionintensity (arbitrary unit). Absorption of the thin film of PCBAPBA wasseen at around 267 nm, around 343 nm, around 379 nm, and around 402 nm.The maximum emission wavelength of the toluene solution was 458 nm (anexcitation wavelength of 400 nm).

From FIG. 30 and FIG. 32, it can be seen that PCBAPBA emits blue lightwith high color purity.

EXAMPLE 5

In this example, a light-emitting element of the present invention isdescribed using FIG. 14. Chemical formulae of materials used in thisexample are shown below.

(Light-Emitting Element 3)

First, indium tin oxide containing silicon oxide was deposited over aglass substrate 1100 by a sputtering method, whereby a first electrode1101 was formed. It is to be noted that the film thickness of the firstelectrode was set to be 110 nm and that the area of the electrode wasset to be 2 mm×2 mm.

Next, the substrate over which the first electrode was formed was fixedto a substrate holder provided in a vacuum deposition apparatus so thata surface on which the first electrode was formed faced downward. Afterthe pressure of the vacuum deposition apparatus was reduced to about10⁻⁴ Pa, a layer 1102 containing a composite material of an organiccompound and an inorganic compound was formed over the first electrode1101 by co-deposition of NPB and molybdenum(VI) oxide. The filmthickness of the layer 1102 was set to be 50 nm, and the weight ratio ofNPB and molybdenum(VI) oxide was adjusted so as to be 4:1(=NPB:molybdenum oxide). It is to be noted that the co-deposition methodis a deposition method in which deposition is carried out from aplurality of evaporation sources at the same time in one treatmentchamber.

Next, NPB was deposited over the layer 1102 containing a compositematerial to a thickness of 10 nm by a deposition method using resistiveheating, whereby a hole-transporting layer 1103 was formed.

Further, by co-deposition of9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (CzPA) and PCBAPBA, alight-emitting layer 1104 was formed over the hole-transporting layer1103 to a thickness of 30 nm. The weight ratio of CzPA and PCBAPBA wasadjusted so as to be 1:0.10 (=CzPA:PCBAPBA).

Thereafter, bathophenanthroline (BPhen) was deposited over thelight-emitting layer 1104 to a thickness of 30 nm by a deposition methodusing resistive heating, whereby an electron-transporting layer 1105 wasformed.

Furthermore, lithium fluoride (LiF) was deposited over theelectron-transporting layer 1105 to a thickness of 1 nm, whereby anelectron-injecting layer 1106 is formed.

Lastly, aluminum was deposited over the electron-injecting layer 1106 toa thickness of 200 nm by a deposition method using resistive heating,whereby a second electrode 1107 was formed. Accordingly, alight-emitting element 3 was fabricated.

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thelight-emitting element 3 are shown in FIG. 33, FIG. 34, and FIG. 35,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 36. From FIG. 36, it can be seen that light emittedfrom the light-emitting element was from PCBAPBA. A CIE chromaticitycoordinates of the light-emitting element 3 at luminance of 950 cd/m²were (x, y)=(0.15, 0.12), which are indicative of blue light with highcolor purity. The external quantum efficiency of the light-emittingelement 3 measured at luminance of 950 cd/m² was 3.7%, which isindicative of high external quantum efficiency. From FIG. 35, it can beseen that the current efficiency of the light-emitting element 3measured at luminance of 950 cd/m² was 3.9 cd/A, which is indicative ofhigh luminous efficiency. From FIG. 34, the driving voltage of thelight-emitting element 3 measured at luminance of 950 cd/m² was 3.2 V,and a voltage needed to obtain a given luminance is low. Furthermore,the power efficiency of the light-emitting element 3 was 3.9 lm/W, andthus, it is found that power consumption for the light-emitting element3 is low.

This application is based on Japanese Patent Application serial no.2007-115079 filed with Japan Patent Office on Apr. 25, 2007, andJapanese Patent Application serial no. 2008-011127 filed with JapanPatent Office on Jan. 22, 2008, the entire contents of which are herebyincorporated by reference.

What is claimed is:
 1. An anthracene derivative represented by a generalformula (1),

wherein Ar¹ and Ar² each represent a substituted or unsubstituted arylgroup having 6 carbon atoms, wherein α represents a substituted orunsubstituted phenylene group or a substituted or unsubstitutedbiphenylene group, wherein β represents a substituted or unsubstitutedarylene group having 6 to 25 carbon atoms, wherein R¹ represents analkyl group having 1 to 4 carbon atoms or a substituted or unsubstitutedaryl group having 6 to 25 carbon atoms, wherein R² represents one ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group, and wherein R¹¹ to R¹⁸ each represent hydrogen oran alkyl group having 1 to 4 carbon atoms.
 2. The anthracene derivativeaccording to claim 1, wherein Ar¹ is a phenyl group.
 3. The anthracenederivative according to claim 1, wherein Ar² is represented by astructural formula (301), and

wherein R³ to R⁷ each represent one of hydrogen, an alkyl group having 1to 4 carbon atoms, a halogen group, and a haloalkyl group.
 4. Theanthracene derivative according to claim 1, wherein Ar² is a phenylgroup substituted by a naphthyl group.
 5. The anthracene derivativeaccording to claim 1, wherein β is represented by any one of Previouslypresented


6. A light-emitting element comprising: a first electrode; a layercomprising an anthracene derivative over the first electrode; and asecond electrode over the layer, wherein the anthracene derivative isrepresented by a general formula (1),

wherein Ar¹ and Ar² each represent a substituted or unsubstituted arylgroup having 6 carbon atoms, wherein α represents a substituted orunsubstituted phenylene group or a substituted or unsubstitutedbiphenylene group, wherein β represents a substituted or unsubstitutedarylene group having 6 to 25 carbon atoms, wherein R¹ represents analkyl group having 1 to 4 carbon atoms or a substituted or unsubstitutedaryl group having 6 to 25 carbon atoms, wherein R² represents one ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted orunsubstituted aryl group having 6 to 25 carbon atoms, a halogen group,and a haloalkyl group, and wherein R¹¹ to R¹⁸ each represent hydrogen oran alkyl group having 1 to 4 carbon atoms.
 7. The light-emitting elementaccording to claim 6, wherein Ar¹ is a phenyl group.
 8. Thelight-emitting element according to claim 6, wherein Ar² is representedby a structural formula (301), and

wherein R³ to R⁷ each represent one of hydrogen, an alkyl group having 1to 4 carbon atoms, a halogen group, and a haloalkyl group.
 9. Thelight-emitting element according to claim 6, wherein Ar² is a phenylgroup substituted by a naphthyl group.
 10. The light-emitting elementaccording to claim 6, wherein β is represented by any one of formulae(β-1) to (β-10),


11. The light-emitting element according to claim 6, wherein the layeris a light-emitting layer.